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Updated: 22 hours 52 min ago

Can exercise offset some of the harms of regular drinking?

Fri, 08/09/2017 - 17:28

"Adults who booze regularly but exercise for five hours a week are no more likely to die than teetotallers," the Mail Online reports.

A study suggests exercise may compensate for some, but certainly not all, of the harms associated with excessive alcohol consumption. This latest study looked at deaths from cancer and cardiovascular disease, as well as premature death in general (usually judged to be dying before the age of 75).

Researchers looked at around 10 years' worth of national survey data from UK adults aged over 40. Unsurprisingly, they found links between all-cause and cancer mortality in inactive people. But they also found increasing levels of physical activity generally removed the association with drinking habits. In fact, occasional drinking was associated with a significant reduction in all-cause mortality for the most active of people.

Although the study had strengths in its large sample size and regular follow-up, we can't be sure that any links observed were solely down to the interaction between alcohol and exercise. For example, people who are physically active may also avoid smoking and consume healthy diets. It is difficult to completely control for such influences when analysing data like this.

While regular exercise may mitigate against some of the harms associated with excessive alcohol consumption it certainly won't make you immune. Many world-class sportspeople, such as George Best and Paul Gascoigne, have had both their careers and lives blighted by drinking.


Where did the story come from?

The UK-based study was carried out by an international collaboration of researchers from Canada, Australia, Norway and the UK. The health surveys on which the study was based were commissioned by the Department of Health, UK. Individual study authors also reported receiving funding from the National Health and Medical Research Council and University of Sydney. 

The study was published in the peer-reviewed British Journal of Sports Medicine. 

The media coverage around this topic was generally overly optimistic, highlighting that by exercising, individuals can completely undo the harm caused by excessive alcohol consumption, which is untrue.

In particular, the Mail Online claimed "Adults who booze regularly but exercise for five hours a week are no more likely to die than teetotallers" which could send out the wrong message to the public.


What kind of research was this?

This cohort study analysed data from British population-based surveys: Health Survey for England (HSE) and the Scottish Health Survey (SHS) to investigate whether physical activity is able to moderate the risk between alcohol consumption and mortality from cancer and cardiovascular diseases.

Cohort studies like this are useful for assessing suspected links between an exposure and outcome. However, there are potentially other factors that have a role to play in such associations and therefore the study design doesn't allow for confirmation of cause and effect.


What did the research involve?

The researchers collected data on 36,370 men and women aged 40 or above from Health Survey for England (1994; 1998; 1999; 2003; 2004; and 2006) and the Scottish Health Survey (1998 and 2003). Among other things, the participants were asked about their current alcohol consumption and physical activity.

Alcohol intake was defined by six categories (UK units/week):

  • never drink (lifetime abstainers)
  • ex-drinkers
  • occasional drinkers (haven't drank anything in past seven days)
  • within (previous) guidelines: <14 units (women) and <21 units (men)
  • hazardous: 14-15 units (women) and 21-19 units (men)
  • harmful: >35 (women) and >49 (men)

Frequency and type of physical activity in the past four weeks was questioned and converted into metabolic equivalent task-hour (MET-hours, which are an estimate of metabolic activity) per week according to national recommendations:

  • inactive (≤7 MET-hours)
  • lower level of active (>7.5 MET-hours)
  • higher level of active (>15 MET-hours)

The surveys were linked to the NHS Central Register for mortality data and the participants were followed up until 2009 (HSE) and 2011 (SHS). There were 5,735 recorded deaths; deaths from cancer and cardiovascular disease were of most interest for this study.

The data was analysed for associations between alcohol consumption and the risk of death from all-causes, cancer and cardiovascular disease. The results were then analysed according to levels of physical activity.

Potential confounders (such as sex, body mass index and smoking status) were controlled for.


What were the basic results?

Overall, the study found a direct link between all levels of alcohol consumption and risk of cancer mortality. It also found that increasing levels of physical activity reduced this association with cancer mortality, and also reduced the link with death from any cause.

  • In individuals who reported inactive levels of physical activity (≤7 MET-hours), there was a direct association between alcohol consumption and all-cause mortality.
  • However, in individuals who met the highest level of physical activity recommendations a protective effect of occasional drinking on all-cause mortality was observed (hazard ratio: 0.68; 95% confidence interval (CI): 0.46 to 0.99). It should be noted that this result just skimmed the cut-off point for statistical significance.
  • In this high activity group, there was no link between all-cause mortality and alcohol consumption within guidelines, or even hazardous amounts, but the risk was still increased for those drinking harmful amounts.
  • The risk of death from cancer increased with the amount of alcohol consumed in inactive participants, ranging from a 47% increased risk for those drinking within guidelines to 87% increased risk for those with harmful drinking.
  • In people with higher activity levels (above 7.5 MET hours) there was no significant link between any amount of alcohol consumption and cancer mortality.
  • No association was found between alcohol consumption and mortality from cardiovascular disease, although a protective effect was observed in individuals who reported the lower and higher levels of physical activity (>7.5 MET-hours) and (>15 MET-hours) respectively.


How did the researchers interpret the results?

The researchers concluded "we found evidence of a dose–response association between alcohol intake and cancer mortality in inactive participants but not in physically active participants. [Physical activity] slightly attenuates the risk of all-cause mortality up to a hazardous level of drinking."



This study aimed to explore whether physical activity is able to moderate the risk between alcohol consumption and mortality from cancer and cardiovascular diseases. It found that increasing levels of physical activity reduced the association for death from both all-causes and cancer.

This study has strengths in its large sample size, comprehensive assessments and long duration of follow-up. The findings are interesting, but there a few points to bear in mind:

  • As the authors mention, cohort studies such as this are unable to confirm cause and effect. Though the researchers have tried to account for various potential health and lifestyle confounding variables, there is the possibility that others are still influencing the results. A notable one is dietary habits which weren't assessed. Also, for example, the former drinkers may have quit due to other health issues which may have introduced bias.
  • The study was unable to look at binge drinking levels of alcohol consumption which would have likely had important health implications.
  • Additionally, there is always the possibility with self-reported surveys that the participants either under or over-reported their drinking habits which can increase the chance of misclassification bias.
  • Though having a large sample size, fewer people reported harmful drinking levels, so links within this category may be less reliable.
  • The study has only looked at the link between alcohol and actually dying from cancer or cardiovascular disease. Links may be different if they looked at associations between alcohol and just being diagnosed with cancer or heart disease, for example.
  • The study is also only representative of adults over the age of 40.

Overall, maintaining a healthy lifestyle seems to be the best bet for reducing the risk of any chronic disease, be it through physical activity, balanced diet or reasonable alcohol consumption.

Current alcohol recommendations for both men and women are to drink no more than 14 units per week.  

Links To The Headlines

How exercise undoes the harm from drinking: Adults who booze regularly but exercise for five hours a week are no more likely to die than teetotallers. Mail Online, September 8 2016

Two hours a week of exercise could offset the dangers of alcohol. The Daily Telegraph, September 8 2016

Exercise can cut risk from alcohol-related diseases, study suggests. The Guardian, September 8 2016

Links To Science

Perreault K, Bauman A, Johnson N, et al. Does physical activity moderate the association between alcohol drinking and all-cause, cancer and cardiovascular diseases mortality? A pooled analysis of eight British population cohorts. British Journal of Sports Medicine. Published online August 31 2016

Categories: NHS Choices

Women taking the contraceptive pill 'more likely to be depressed'

Fri, 30/09/2016 - 17:30

"Are you on the Pill? You're more likely to be depressed: Women who use contraception are up to 70% more likely to be on antidepressants," reports the Mail Online.

The news is based on a study by researchers in Denmark to see whether hormonal contraceptive methods were associated with depression. More than 1 million women aged 15 to 34, with no prior history of depression, were included in the study.

The researchers found that, compared to non-users, those who took the pill were 23% more likely to use antidepressants.

However, it's important to note this study is not able to prove that the contraceptive methods are responsible for the depression, only to find possible links to investigate further.

The researchers don't advise that women should stop using their contraception, just that further studies are needed. If this association is found to be true, depression may have to be added as a possible side effect of hormonal contraception. 

Where did the story come from?

The study was carried out by researchers from the University of Copenhagen and was funded by the University of Copenhagen and the Lundbeck Foundation.

The study was published in the peer-reviewed medical journal JAMA Psychiatry.

The study authors revealed that Dr Kessing had consulted for Lundbeck and AstraZeneca and receiving honoraria for this work, while Dr Lidegaard received honoraria for talks within the past three years from Exeltis.

The story was reported accurately in the media, with The Telegraph stating: "The Danish study didn't aim to show that the Pill directly causes depression. But it does point to a worrying association between women taking the contraceptive and those also being prescribed an antidepressant." This is useful to note as this kind of study is not able to prove cause and effect.

What kind of research was this?

This was a large prospective cohort study which aimed to investigate whether the use of hormonal contraception is associated with future use of antidepressants and diagnosis of depression.

This type of study is able to provide possible links between the exposure and outcome, but is not able to prove that one causes the other. It remains possible that other factors, such as concerns over pregnancy, or taking regular medication, might contribute to the outcome.

What did the research involve?

The researchers used data from the National Prescription Register and the Psychiatric Central Research Register in Denmark.

Women and girls aged between 15 and 34 years of age, living in Denmark, were followed up from January 1 2000 to December 2013. They were excluded from the study if they had:

  • a previous diagnosis of depression
  • been prescribed antidepressants
  • another major psychiatric diagnosis
  • cancer
  • venous thrombosis
  • infertility treatment

Contraceptive methods were categorised by oestrogen type and dose, progesterone type and the method of contraception. Data was collected from the National Prescription Register.

Data for the use of antidepressants was collected using two outcome measures:

  • collecting a prescription for antidepressants
  • being diagnosed with depression at any inpatient or outpatient psychiatric department in Denmark

Non-users were defined as those who never used hormonal contraceptives, plus former users.

What were the basic results?

The analysis included 1,061,997 women, with an average age of 24 years. During follow-up, 55.5% of women were current or recent users of hormonal contraception. A total of 133,178 first prescriptions of antidepressants and 23,077 first diagnoses of depression were detected during follow-up.

The researchers compared users of hormonal contraception with non- users and found more users had been prescribed antidepressants or diagnosed with depression.

They calculated the increase in risk of using antidepressants according to contraceptive method as:

Similar figures were found for depression diagnoses.

The researchers also found the risk of depression decreased with age. Adolescents using combined oral contraceptives had an 80% increased risk of antidepressant use (RR 1.8 (95% CI, 1.75 to 1.84)) and those using progesterone-only pills a 120% higher risk (RR 2.2 (95% CI, 1.99 to 2.52)).

How did the researchers interpret the results?

The researchers concluded that the "use of hormonal contraception, especially among adolescents, was associated with subsequent use of antidepressants and a first diagnosis of depression, suggesting depression as a potential adverse effect of hormonal contraceptive use."


This was a large prospective cohort study which aimed to investigate whether using hormonal contraception is associated with the future use of antidepressants and a diagnosis of depression.

The researchers compared users of hormonal contraception with non-users and found users were more likely to be prescribed antidepressants and diagnosed with depression.

However, there are a few important points to consider about the results, such as:

  • this study is not able to prove that the contraceptive methods are responsible for the depression – only to find possible links to investigate further
  • some of the associations are based on a comparatively small number of events
  • the risk of using antidepressants and being diagnosed with depression peaks at approximately two to three months of contraceptive use, but then begins to fall

The researchers tested for a range of other things that might explain the results. For example, they looked at whether doctors were more likely to prescribe hormonal contraception to women who were already low in mood, or whether the initiation of a sexual relationship might influence the risk of depression. They found nothing that could easily explain the link that was shown across all age groups and types of contraception.

Further studies are required to prove this link. If the link is proven in future studies, depression may have to be added as a possible side effect of hormonal contraception.

Links To The Headlines

Women taking pill more likely to be treated for depression, study finds. The Guardian, September 28 2016

Are you on the Pill? You're more likely to be depressed: Women who use contraception are up to 70 per cent more likely to be on antidepressants. Mail Online, September 28 2016

Is the contraceptive Pill making you feel depressed? The Daily Telegraph, September 29 2016

Links To Science

Skovlund CW, Mørch LS, Kessing LV, et al. Association of Hormonal Contraception With Depression. JAMA Psychiatry. Published online September 28 2016

Categories: NHS Choices

Ibuprofen-like painkillers linked to an increased risk of heart failure

Thu, 29/09/2016 - 17:30

"Ibuprofen could raise the risk of heart failure by up to 83%," claims the Daily Mirror. But this headline massively overstates the danger of this painkiller.

In fact, new research suggests that taking painkillers known as non-steroidal anti-inflammatory drugs (NSAIDs) – which includes ibuprofen – increases the risk of heart failure by less than 20% overall.

NSAIDs are a group of painkilling medicines commonly taken by people with joint problems, backache and arthritis. They are prescribed to relieve pain and reduce inflammation.

The study found that the risk of heart failure varies between NSAIDs and according to dosage.

While a rarely prescribed NSAID called ketorolac almost doubled the risk of heart problems, the more commonly taken ibuprofen increased the chance of heart problems by just 18%.

The risk was also highest for people who took an NSAID on a daily basis and in very high doses.

Some NSAIDs, such as ketoprofen and celecoxib, did not seem to increase the risk at all at usual doses.

This latest study backs up previous evidence that NSAIDs are clearly linked with an increased risk of heart failure. But it's important to bear in mind that the risk is, for most people, still very small.

Heart failure is caused by a wide range of conditions, including high blood pressure, heart attacks and obesity.

Where did the story come from?

This was a large study involving more than 7 million people. It was carried out by researchers from seven European institutions, led by the University of Milan, and was funded by the European Union. The study was published in the peer-reviewed British Medical Journal (BMJ).

Some UK media outlets failed to make it clear the study was carried out among people who were taking prescribed NSAIDs, usually for a long-term condition such as backache or arthritis, rather than people taking the occasional over-the-counter painkiller.

The Daily Express headline wrongly says: "Over-the-counter painkillers raise risk by almost 20%," although at least they used the more credible 20% relative risk figure.

The Daily Mirror's scaremongering headline stating an increased risk of heart failure of 83% was way above that of most of the NSAIDs studied and was wrongly linked to ibuprofen.

BBC News took a more balanced view, and included interviews with experts who discussed exactly who is and isn't at risk from NSAIDs and heart failure.

What kind of research was this?

This was a so-called nested case-control study, which used drug databases to identify people who'd been prescribed NSAIDs during a 10 year period. Of these, those who had been admitted to hospital for heart failure were compared with others in the database of the same age and sex.

This type of study helps researchers identify links between individual drugs and outcomes such as heart disease. They don't directly prove the drug causes the heart disease, but we've already seen randomised controlled trials showing NSAIDs in general do seem to raise the chances of heart failure.

What did the research involve?

Researchers used five drug databases from four European countries to identify adults who'd had at least one NSAID prescription between 2000 and 2010. They then identified anyone from that group who'd later been admitted to hospital with heart failure and matched them with up to 100 "controls" – people the same age and sex, who'd started the study around the same time.

They then looked to see whether a current prescription of an NSAID (within the last 14 days) affected someone's chances of being admitted to hospital with heart failure.

The databases were from the UK, Italy, the Netherlands and Germany. For the UK and the Netherlands, the databases also recorded the daily dose prescribed, so the researchers used this information to calculate the effect of low, normal, high or very high prescribed doses.

The researchers corrected their figures to take account of factors such as previous diagnosis of heart failure or other medical condition and other medicines being taken.

What were the basic results?

The study found 92,163 people who'd been admitted to hospital with heart failure among the 7.6 million people prescribed an NSAID who were included in the study. People admitted with heart failure tended to be older, with an average age of 77, and many of them also had high blood pressure, high cholesterol, cardiovascular disease or diabetes.

Compared to others of about the same age and sex, those who'd been admitted for heart failure were more likely to be currently taking a prescribed NSAID.

In fact, nearly one in five (17.4 %) of heart failure patients and one in seven (14.4 %) of the matched control groups had a current prescription. This meant that having a current prescription for any NSAID raised the risk of heart failure admission by almost 20% (odds ratio (OR) 1.19, 95% confidence interval (CI) 1.17 to 1.22).

However, more interesting was the information about individual drugs. Nine NSAIDs had a raised risk of heart failure: ketorolac, etoricoxib, indomethacin, rofecoxib, piroxicam, diclofenac, nimeluside, ibuprofen and naproxen.

The degree of increased relative risk varied between them, from ketorolac at 83% to naproxen at 16%.

Some of the NSAIDs, including the commonly used ketoprofen and celeocoxib, did not show any increased risk.

The risk was highest for people taking very high daily doses (twice the usual daily dose) of NSAIDs.

How did the researchers interpret the results?

The researchers said their study results showed that the risk of heart failure in people taking NSAIDs "appears to vary between individual NSAIDs, and is dose dependent". 

They say their findings "might apply to NSAIDs obtained over the counter", although they only looked at prescription drugs.

"Although over-the-counter NSAIDs are probably typically used at lower doses, by younger people, and for shorter durations than prescribed NSAIDs, they are sometimes available at the same doses," they observe, adding "they may be inappropriately over-used".

They call for research into the safety of over-the-counter NSAIDs "under the conditions they are typically used".


This useful and well-conducted study isn't the first to say NSAIDs may raise the risk of heart failure. We've known for some time that NSAIDs can have side effects, especially when used at high doses and for long periods.

What this study does help show is the different levels of risk between different NSAIDs, and confirms that the risk depends partly on the dose. It's important to remember that the study only included people who were prescribed NSAIDs and not people who'd bought them over the counter.

The information is most useful to older people taking prescribed NSAIDs long-term for conditions such as gout or arthritis. These are the people most likely to be affected by heart problems linked to NSAIDs.

The study shows that some NSAIDs are less risky than others, and doctors can use this information to discuss with patients which is the most suitable drug if they need long-term anti-inflammatory painkillers.

For people who take NSAIDs over the counter, it's a reminder that these drugs are not risk-free. While an otherwise healtlhy 20-something taking ibuprofen for a day or two to get over backache is highly unlikely to get heart failure as a result, long-term use of NSAIDs at high doses can cause problems.

Sensible advice is to take the lowest dose that works for the shortest period you need it. If you find you need to take NSAIDs very often, or you're taking doses higher than those recommended, you should talk to your doctor about your pain.

Find out more about living with pain.

Links To The Headlines

Ibuprofen link to heart failure: Over-the-counter painkillers raise risk by almost 20%. The Daily Express, September 29 2016

Ibuprofen increases heart risk by a fifth. The Times, September 29 2016

Common painkillers 'increase heart failure risk'. BBC News, September 29 2016

Painkillers like ibuprofen may raise risk of hospital admission for heart failure. The Telegraph, September 29 2016

Links To Science

Corrao G, Arfe A, Scotti L et al. Non-steroidal anti-inflammatory drugs and risk of heart failure in four European countries: nested case control study. The British Medical Journal. Published Online 28 September 2016

Categories: NHS Choices

Acne won't extend your life, but might delay signs of ageing

Wed, 28/09/2016 - 15:00

"Spotty teenagers may have the last laugh over their peers with perfect skin after research found that those who suffer from acne are likely to live longer," says The Telegraph online.

But the report misunderstands the research findings, which were related to cell ageing, not length of life.

The researchers state dermatologists have for many years noticed that people who have had acne show signs of ageing later than those who have never had the skin condition.

Signs of ageing are cited as the appearance of wrinkles and thinning of the skin. This new study looked at why that might be. 

The researchers found, by analysing white blood cells, that women who said they'd had acne had longer telomeres, the "caps" at the end of chromosomes.

Cells replicate repeatedly, and telomeres are thought to protect them from deterioration as a result of this process. The Telegraph likened these caps to the hard tips on shoelaces that prevent fraying.

While this study doesn't show that telomere length is a cause of acne, it shows there may be a link between the two.

However, the study didn't look at whether the women with longer telomeres had fewer signs of skin ageing, or whether they lived longer. The suggestion that acne could affect how long you live is therefore unfounded.

Where did the story come from?

The study was carried out by researchers from King's College London and New Jersey Medical School, and was funded by the Wellcome Trust, the Medical Research Council, the European Union and the National Institute for Health Research. 

The study was published in the peer-reviewed Journal of Investigative Dermatology.

Mail Online, ITV News, The Daily Telegraph and BBC newsbeat got the thrust of the story right: that acne is linked to longer telomeres, which may explain why some people who've had acne have younger-looking skin as they get older.

Only The Telegraph online suggested acne could help you live longer. This idea is not mentioned in the study or in the press release from the authors.

What kind of research was this?

This study used two methods: a cohort study and a case control study

Researchers took a group of women, identified those who reported having acne at some point in their lives, and compared the length of telomeres taken from their white blood cells with telomeres from women who said they'd never had acne.

They also carried out a case control study comparing gene expression in women who'd had acne with women the same age who had not reported having ever had the skin condition.

This type of research can start to identify links between factors such as telomere length and acne, but can't prove that one causes the other.

What did the research involve?

Researchers recruited 1,205 volunteers from TwinsUK, a registry of 12,000 twins used to study the genetic and environmental causes of age-related traits and diseases. The registry involves mainly women, so men were excluded from the study.

Researchers who are interested in the genetic basis of conditions often work with twins, as it helps identify which factors are down to environment and which are down to a shared genetic profile.

Researchers asked the participants if they had ever had acne. Participants provided samples of white blood cells, which were then analysed for telomere length.

After adjusting their figures for age, twin relationships, weight and height, the researchers compared average telomere length between the two groups.

Separately from the telomere study, researchers age-matched 195 twins without acne to 39 twins with acne, took skin biopsies, and used their whole genome data to compare gene expression – whether a gene is "switched on" or not – between the groups.

What were the basic results?

Women who'd had acne had, on average, longer telomeres (mean 7.17 +/- 0.64 kilobases [kb]) than women who'd not had acne (mean 6.92+/- 0.02kb) after the figures had been adjusted for the women's age, weight and height.

Telomere lengths are calculated in kilobases, referring to the number of six base-pair sequences of DNA found in telomeres.

Only one gene (ZNF420) was more commonly expressed in women without acne than women who'd had acne.

How did the researchers interpret the results?

The researchers say longer telomeres in women who've had acne suggest that "delayed skin ageing may be due to reduced senescence" – in other words, skin ageing may be delayed because the longer telomeres in the cells protect them from deterioration.

They go on to say the reduced expression of the regulatory gene ZNF420 in people with acne suggests these people may produce more of a particular protein linked to that gene.


Acne can be very distressing for teenagers and those who get it later in life. It may be some comfort to know that people with acne tend to show fewer signs of skin ageing, such as wrinkles and thin skin, when they get older.

The link between telomere length and acne is interesting for researchers, but doesn't mean that much for the rest of us.

It may be part of the explanation for slower skin ageing in people who've had acne. And it adds weight to the theory that there's a genetic component to acne.

But the study doesn't tell us whether people who'd had acne and had longer telomeres actually had younger-looking skin.

The article was published as a letter to the editor and is much shorter than most research articles, so does not give us a lot of information about how the study was carried out.

The study only included women, so we don't know if it would also apply to men. And it also relied on women saying they'd had acne, rather than on a medical diagnosis, so there may be some variation in whether women thought they'd had acne or not.

If you're concerned about acne, there are plenty of self-help methods you can try, or you can talk to a pharmacist for advice on over-the-counter treatments.

If it's making you very unhappy and these methods aren't working, talk to your GP.

Find out more about acne and how to treat it

Links To The Headlines

Acne sufferers live longer, research suggests. The Telegraph, September 28 2016

Why being a spotty teenager stops your skin ageing: Acne sufferers' cells have built-in protection that keeps them looking younger. Mail Online, September 28 2016

Teens with spots tend to stay looking younger for longer, new research suggests. BBC newsbeat, September 28 2016

Acne sufferers stay youthful-looking for longer. ITV News, September 28 2016

Links To Science

Ribero S, Sanna M, Visconti A, et al. Acne and telomere length, a new spectrum between senescence and apoptosis pathways. The Journal of Investigative Dermatology. Published online September 2016.


Categories: NHS Choices

Could riding roller coasters help you pass kidney stones?

Tue, 27/09/2016 - 15:00

"Got kidney stones? Ride a roller coaster! Study shows it is the most pain-free cost-efficient way to pass them," says the Mail Online of a study carried out in the US which tested riding roller coasters as a way of passing kidney stones.

The study came about after a number of people with kidney stones claimed riding on Walt Disney World's Big Thunder Mountain Railroad ride had helped them pass their stones. In particular, one person with kidney stones reported passing a stone after each of three consecutive rides. This prompted a research team from Michigan State University, led by Dr David Wartinger, to investigate further.

The researchers rode the Big Thunder Mountain Railroad ride a total of 60 times carrying a 3D printed model kidney made from silicone. The kidney contained urine and kidney stones of three different sizes.

They found that the rides caused the kidney stones to be passed from the kidney, and that the position on the ride made a big difference to the number of stones passed. Sitting at the back of the ride produced the best results.

A key limitation of the study is that the research was carried out on a model kidney rather than on the kidneys of real people. This method can never truly replicate the behaviour of the stones in a real kidney. However, the findings may support the case for further research into what it is about the ride that might cause stones to pass.

Where did the story come from?

The study was carried out by researchers from Michigan State University, who reported no source of funding for the study. 

The report was published in the peer-reviewed Journal of the American Osteopathic Association.

The Mail Online and The Daily Telegraph presented the main findings of the study but fail to mention any of the limitations of the research.

What kind of research was this?

This was an experimental study which aimed to assess roller coaster rides as a method of passing kidney stones.

Kidney stones are formed when certain chemicals, usually calcium, or uric acid, build up in the body. Some medical conditions can contribute to high levels of these substances being in the body. They are more likely if you don't drink enough fluids.

This study is able to provide possible links for further investigation but can't provide any conclusive evidence that would be applicable to all. The study team appreciate this limitation and were reported in the Mail Online as saying: "The purpose of this initial study was to validate the effectiveness of the model and support the case for further research."

What did the research involve?

The researchers aimed to assess the effectiveness of roller coaster rides for passing kidney stones by creating an anatomical model of the kidney and taking this on a number of rides to test various scenarios of stone position within the kidney and different seating positions on the ride.

The roller coaster, Walt Disney World's Big Thunder Mountain Railroad ride, had a maximum speed of 35mph, took sharp turns and had quick drops. The ride did not go upside down and lasted for two and a half minutes.

The model itself was made of clear silicone to allow direct inspection of the stone location after each ride and was based on the kidney scan of the patient providing the kidney stones for the test.

The stones were suspended in urine within the model and were of three different volumes:

  • 4.5 mm3
  • 13.5 mm3
  • 64.6 mm3

The model was placed in a padded backpack that was positioned at kidney height at the back of the seat on the roller coaster, between the researchers. Data was gathered 20 times for each of the kidney chambers, eight rides in the front seating and 12 in the rear seating. 

What were the basic results?

Sixty roller coaster rides were taken and the effect on the kidney stones analysed.

When the model was carried in the front seating of the roller coaster fewer kidney stones were passed (16.7%) than when sat in the rear seating (63.9%).

The position of the stone also appears to make a difference to the rate of passage. If the stone is in the upper chambers (calyces) of the kidney it is passed more frequently than when it is in the middle or lower chambers. In fact, when the model was carried in the rear of the roller coaster, stones in the upper chamber were passed 100% of the time. 

The size of the stone did not appear to influence the proportion of stones passed.

How did the researchers interpret the results?

The researchers concluded that their model served as a functional patient surrogate to evaluate activities that facilitate the passing of kidney stones. In other words, they could expect the kidneys and kidney stones of real people to behave in the same way as the model. They state that the rear seating position on the roller coaster led to the most kidney stones being passed.


This experimental study assessed going on roller coasters as a means of passing kidney stones.

Prior to this study there had been a number of reports that riding on roller coasters had caused people to pass their kidney stones, with one person claiming to have passed three kidney stones after three consecutive rides on the Big Thunder Mountain Railroad roller coaster at Disney World in Florida.

The researchers found a similar effect using their model, and also saw that the seating position on the ride made a big difference, with almost four times the number of stones passing in the rear of the ride compared to the front.

There are a number of limitations to this research:

  • The study used an anatomical model of the kidney rather than actual people. This will never truly replicate the behaviour of the stones in a real kidney.
  • The model was based on a single person with kidney stones. The anatomy of this person's kidney will not be the same as other peoples' because the anatomy of an individual's kidneys is unique, much like a fingerprint.
  • Only a single roller coaster was used. The same effect may not be seen on other rides with different characteristics.

However, as the research team told the media, this was an initial study to validate the effectiveness of the model and support the case for further research.

Some symptoms of kidney stones to be aware of are:

  • a persistent ache in the lower back
  • periods of intense pain in the back or side of your abdomen
  • feeling sick
  • needing to urinate more often than normal
  • pain when you urinate
  • blood in your urine 

To prevent kidney stones make sure you avoid becoming dehydrated. Drinks such as tea, coffee and fruit juice can count towards your fluid intake, but water is the healthiest option and is best for preventing kidney stones developing. Make sure you drink more when it is hot or when you are exercising, to replenish fluids lost through sweating.

Links To The Headlines

Got kidney stones? Ride a roller coaster! Study shows it is the most pain-free cost-efficient way to pass them Mail Online, September 26 2016

Roller coasters could be a cure for kidney stones The Telegraph, September 26  2016


Links To Science

Mitchell, Marc A, Wartinger, David D Validation of Functional Pyelocalyceal Renal Model for the Evaluation of Renal Calculi Passage While Riding a Roller Coaster. The Journal of the American Osteopathic Association. Published online September 2016

Categories: NHS Choices

Gut bacteria may be linked to 'dangerous' body fat

Mon, 26/09/2016 - 01:00

The BBC reports that: "The make-up of the bacteria found in human faeces may influence levels of dangerous fat in our bodies."

The article is based on a UK study looking at faeces samples taken from twins, and various measures of obesity. The study showed that people who had fewer different types of bacteria in their faeces were more likely to be obese.

The link was strongest for visceral fat, which is stored around the internal organs inside the abdominal cavity. This type of fat is associated with a higher risk of metabolic diseases, such as type 2 diabetes, as well as cardiovascular disease.

The study also found that identical twins were more likely to have similar diversity of bacteria in their faeces than non-identical twins, suggesting it may be partly inherited. This could explain why obesity sometimes passes down through families.

While there's a clear link between bacteria in faeces and visceral fat, it's not yet known how the diversity and type of bacteria influences body fat. Further research is needed.

Eating a balanced diet and having an active lifestyle can help you maintain a healthy weight.

Where did the story come from?

The study was carried out by researchers from the Department of Twin Research and Genetic Epidemiology at King's College London in the UK, the Department of Microbiology and the Department of Molecular Biology and Genetics at Cornell University, and the University of Colorado in the US, and the Max Planck Institute for Developmental Biology in Germany. 

It was funded by the US National Institutes for Health (NIH), the Cornell Center for Comparative Population Genomics, the Wellcome Trust, the European Community's Seventh Framework Programme, the European Research Council, and the National Institute for Health Research (NIHR).

The authors declared no conflicts of interest.

The study was published in the peer-reviewed journal, Genome Biology. It is open access, so it's freely available to read online.

The media reported the story accurately, with the BBC acknowledging that, although there is a link between bacteria in human faeces and levels of obesity, there is no known explanation yet.

What kind of research was this?

This was a cross-sectional observational study carried out on healthy sets of twins.

It aimed to explore the association between the bacteria present in human faeces and obesity.

This type of study can't prove cause and effect, but is useful for looking at associations between risk factors and outcomes.

So while this study doesn't prove that bacteria found in human faeces cause visceral fat, it does show there is a relationship between the two.

What did the research involve?

Researchers studied healthy volunteers involved in the TwinsUK Adult Twin Registry. Data on body fat was collected from a sample of 3,666 twins.

They looked at the links between bacteria found in faeces and six different measures of body fat.

The sample was mostly of European descent, and the average age was 63.

Faeces samples were collected from 1,313 individuals, and the bacteria in these investigated. Almost all those sampled were female.

The information from study participants on the bacteria present in their faeces was compared with body fat levels.

The six body fat measures included three of visceral fat, two of body fat distribution, and one of body mass index (BMI).

Excess visceral fat in particular is a risk factor for cardiovascular disease and metabolic disease, such as type 2 diabetes.

What were the basic results?

All but one measure of obesity were significantly associated with a lack of diversity of bacteria in the faeces.

However, the association was strongest for visceral fat, which is found around the internal organs and is a bigger risk factor for cardiovascular and metabolic diseases.

Researchers found the higher the diversity of bacteria in faeces, the lower the level of visceral fat.

The reverse was also shown: the less diverse the bacteria, the more likely participants were to have more visceral fat.

Visceral fat was found to be highly heritable (relative risk [RR] = 0.70, 95% confidence interval [CI] = 0.58 to 0.74). This was true even when adjustments for body mass index (BMI) were made.

How did the researchers interpret the results?

Dr Michelle Beaumont, lead author of the study from the Department of Twin Research and Genetic Epidemiology at King's, said: "This study has shown a clear link between bacterial diversity in faeces and markers of obesity and cardiovascular risk, particularly for visceral fat.

"However, as this was an observational study we cannot say precisely how communities of bacteria in the gut might influence the storage of fat in the body, or whether a different mechanism is involved in weight gain."

Senior author, Dr Jordana Bell, also from the Department of Twin Research and Genetic Epidemiology, said: "There is a growing body of evidence to suggest that gut bacteria may play a role in obesity, and a number of studies are now exploring this in more detail.

"Further scientific investigation is needed to understand how precisely our gut microbes can influence human health, and if interventions such as faecal transplants can have safe, beneficial, and effective impacts on this process."


This cross-sectional study found a strong association between visceral fat and bacteria diversity in faeces.

The use of measures other than BMI was one of this study's strengths, as BMI doesn't reveal whether weight is from fat tissue or muscle.

The findings suggest that body fat levels may be passed down through families.

However, this is early research and there are a number of things to consider:

  • We don't know how the bacteria in our gut and faeces influence levels of fat in the body.
  • The study doesn't prove that having less diverse bacteria in our faeces causes visceral fat around the organs.
  • Participants' diets weren't taken into consideration.
  • Participants were mainly female and from the UK, so the findings can't be applied across genders or globally.

It's important to eat a balanced diet and have an active lifestyle to maintain a healthy weight.

Links To The Headlines

Body fat link to bacteria in faeces. BBC News, September 26 2016

How gut bacteria may predict belly fat. Time, September 25 2016

Links To Science

Beaumont M, Goodrich J, Jackson M. Heritable components of the human fecal microbiome are associated with visceral fat. Genome Biology. Published 26 September 2016

Categories: NHS Choices

Fitness trackers 'don't help you lose weight'

Fri, 23/09/2016 - 17:28

"Fitness trackers may not help weight loss," reports Sky News on a new trial which investigated whether using wearable technology helped people lose more weight compared to standard weight-loss programmes.

Researchers tracked 470 overweight or obese people aged 18 to 35, for 24 months. Everyone in the study was put on a low-calorie diet, given an exercise plan and invited to regular group counselling sessions.

After six months, half the group was given a wearable device to track activity and feed it into a computer programme that also allows people to record their diet.

The other half were simply told to continue the weight loss programme and monitor their exercise and diet by themselves.

The group using the Fit Core tracker lost an average of 3.5kg over two years, compared with an average 5.9kg in the self-monitored group.

The spread of obesity across the globe has been increasing rapidly in recent years and public health bodies continue to struggle with tackling the issue.

Along with the usual weight-loss diets, the use of wearable technologies promoting fitness, such as FitBit and Jawbone, is also on the rise.

The study authors say there are many possible explanations for their surprising finding but, as yet, no proof.

BBC News quotes lead researcher Dr John Jakicic saying: "People have a tendency to use gadgets like these for a while and then lose interest with time as the novelty wears off.

"And we did see a drop off in the usage data as the study went on."

Although the study's findings are interesting, it may be the case that the use of fitness trackers and other devices may be more effective for some people than others.

Until more conclusive research is available, the best advice for losing weight is to follow a calorie-controlled diet combined with regular exercise.

Where did the story come from?

The study was carried out by researchers from the University of Pittsburgh in the US. It was funded by a grant from the National Institutes of Health and the National Heart, Lung and Blood Institute.

Interestingly, the researchers were affiliated with Weight Watchers International.

The findings from the trial were published in the peer-reviewed medical journal JAMA. It is free to read online.

Generally, media coverage around this topic was accurate.

What kind of research was this?

This was a randomised controlled trial (RCT) which aimed to compare the effectiveness of a wearable technology weight loss intervention (fitness tracker) with standard weight loss strategies to see which would result in greater weight loss.

RCTs such as this are one of the best ways to investigate the effectiveness of public health interventions.

In such trials there is the possibility that the individuals' knowledge of being monitored by the wearable technology could influence their diet, activity and weight loss. This is known as being non-blinded to the intervention group, which can normally be a potential source of study bias. However, in this case it's probably just part of the way the intervention was intended to work.

What did the research involve?

The 24-month Innovative Approaches to Diet, Exercise and Activity (IDEA) randomised controlled trial at the University of Pittsburgh recruited 471 participants (aged 18-35) with a body mass index (BMI) between 25.0 and 40.0.

Participants were randomised to one of two treatment groups: a standard behavioural weight loss intervention and a weight loss intervention enhanced by using wearable technology.

For the first six months both groups received the same behavioural weight loss intervention and were instructed to self-monitor dietary intake and their physical activity in diaries. This information was given to the study staff who offered feedback.

At six months, the standard behavioural weight loss group started self-monitoring their diet and physical activity via an website designed for the trial. No feedback was given. At this time, the enhanced intervention group were given their wearable technology device which had access to education materials via a web-based interface (BodyMedia FIT Core). This monitored their diet and physical activity.

During months 7-24, both groups also received telephone counselling sessions, text message prompts and access to online study materials.

The main outcome of the study was to assess weight change at 24 months. Participants were also assessed at months 0, 6, 12 and 18, and received monetary compensation for completing each assessment. The researchers analysed the findings between both treatment groups.

What were the basic results?

Overall, there was significant weight change over time in both treatment groups. However, there was greater weight loss in the standard behavioural intervention group compared with the technology-enhanced intervention.

  • The average weight loss between baseline and 24 months in the standard behavioural intervention group was 5.9kg (95% confidence interval (CI): 5.0 to 6.8).
  • In the technology-enhanced intervention group, the average weight loss over the same time was 3.5kg (95% CI: 2.7 to 4.5).
  • The difference between the two groups was 2.4kg (95% CI: 1.0 to 3.7).

Additionally, there was a greater decrease in body fat (%) in the standard behavioural intervention group compared with the technology-enhanced intervention.

  • The average loss of body fat (%) between baseline and 24 months in the standard intervention was 3.5% (95% CI: -4.0 to –3.0).
  • The enhanced intervention group lost on average 2.4% body fat (95% CI: -3.0 to -1.9).
  • The difference between the two groups was -1.1% in body fat (95% CI: -1.9 to -0.3).
How did the researchers interpret the results?

Researchers concluded: "Among young adults with a BMI between 25 and less than 40, the addition of a wearable technology device to a standard behavioural intervention resulted in less weight loss over 24 months. Devices that monitor and provide feedback on physical activity may not offer an advantage over standard behavioural weight loss approaches."


This trial aimed to compare the effectiveness of a wearable technology weight loss intervention (fitness tracker) with standard weight loss strategies to see which would result in greater weight loss at the end of 24 months.

It found the addition of a wearable technology device did not aid weight loss, and participants in the standard behavioural intervention group lost more weight when compared to the technology group.

This was an interesting study with a reliable study design. However there are a few things to note:

  • As the authors mention, the participants were all young adults (mean age 30) and 77.2% were women so these findings are not representative of the general population.
  • Although this trial showed weight loss over a 24 month period, the greatest weight loss was achieved in the first six months and this was not fully sustained over the long-term. Therefore, the challenges of maintaining weight loss continue to exist.
  • The adoption of the wearable technology device was started six months into the intervention so the findings may have been different had the participants started using them at baseline.

Links To The Headlines

Fitness trackers offer no weight-loss benefit and can make users fatter, says study. The Daily Telegraph, September 21 2016

'No proof' fitness trackers promote weight loss. BBC News, September 20 2016

Fitness trackers may not help weight loss. Sky News, September 21 2016

Fitness trackers may not aid weight loss, study finds. The Guardian, September 21 2016

Study finds fitness trackers don't pull their weight. The Daily Mail, September 21 2016

Links To Science

Jakicic JM, Davis KK, Rogers RJ et al. Effect of Wearable Technology Combined With a Lifestyle Intervention on Long-term Weight Loss: The IDEA Randomized Clinical Trial. Published September 21 2016

Categories: NHS Choices

GM chemicals in cleaning products are 'potent allergens'

Thu, 22/09/2016 - 17:28

"GM enzymes used in household products 'are potent allergens'," reports The Daily Mail following research on the potential for genetically modified enzymes to cause allergies.

Researchers took blood samples from 813 workers routinely exposed to genetically modified (GM) enzymes from working in the food, drinks, chemicals, detergents and pharmaceutical industries.

They found antibodies – proteins produced in response to the presence of the GM enzymes – in just under a quarter of those tested. 

The most commonly detected antibodies were derived from exposure to alpha amylase, stainzyme, and pancreatinin, which are predominantly used in detergents and home care products.

However, just having antibodies doesn't prove a person has an allergy.

The researchers examined a subgroup of 134 workers and found around a third of them had possible allergic symptoms such as runny nose, eye irritation or shortness of breath.

One-off tests on these workers do not give conclusive proof that exposure to these enzymes causes allergies.

Also, these workers are likely to have a higher level of exposure through their occupation than the average person may have just by using such products.

Therefore the findings do not give immediate cause for concern for the general public.

Nevertheless, if these findings are verified, further regulation around products containing such enzymes may be required.

Where did the story come from?

The study was carried out by researchers from the University Medical Center Hamburg-Eppendorf. There was no mention of a source of funding for this study.

The report was published in the peer-reviewed journal Occupational & Environmental Medicine and is free to read online.

The media reported on this study accurately. The Guardian provides a good summary of the research and findings, rightfully pointing out limitations of the research such as the possibility of selection bias in the subgroup analysis.

What kind of research was this?

This was a cross sectional study which aimed to investigate genetically engineered enzymes – such as those used in manufacturing fragrances, detergents and food flavourings – as potential allergy-causing substances (allergens).

As this was a cross sectional study, taking one-off allergy tests in staff in the workplace, it cannot prove causation. However, this type of study is useful for providing links for further investigation.

A cohort study, assessing allergic response in people before they started working in these industries, and then following them up over time to see how their allergic response changes, would give better indication of cause and effect.

What did the research involve?

The researchers took blood samples from 813 workers exposed to genetically modified enzymes. Most of the workers were from the food, chemical, detergent and pharmaceutical industries. Two-thirds were men aged 20 to 60 years.

The blood samples were screened for antibodies related to enzyme exposure in their workplace. The specific enzyme antibodies were:

  • phytase
  • xylanase
  • glucanase
  • cellulose
  • savinase and/or alpha-amylase

The workers were exposed for between three months and 10 years to two to four enzymes in their workplaces.

For a subgroup of 134 workers at two workplaces, clinical data was collected, including their medical histories, physical examination and lung function testing.

What were the basic results?

Just under a quarter (23%) of all exposed workers had IgE antibodies related to workplace-specific enzymes. These are the antibodies the immune system produces as an allergic response.

The most common antibodies were against the enzymes derived from alpha-amylase (44%), followed by stainzyme (41%) and pancreatinin (35%).The highest individual antibody levels were detected in workers exposed to phytase, xylanase and glucanase.

Alpha amylase, stainzyme, and pancreatinin are predominantly used in detergents, cleaning products and home care products.

The sub group analysis found that 64% were symptom free, 19% had a runny nose and/or conjunctivitis, and 17% had wheezing and/or shortness of breath.

How did the researchers interpret the results?

The researchers conclude: "Our data confirm the previous findings showing that genetically engineered enzymes are potent allergens eliciting immediate-type sensitisation. Owing to lack of commercial diagnostic tests, few of those exposed receive regular surveillance including biomonitoring with relevant specific IgE [tests]."


This cross sectional study aimed to assess the potential for allergy caused by genetically modified enzymes which are abundant across the manufacturing industry.

The researchers showed that such enzymes can cause increased levels of the related antibodies, causing sensitisation for some of those that come in contact. However, just having antibodies to something you've been exposed to doesn't necessarily equate to allergic symptoms such as dermatitis or asthma.

A notable limitation of this study is that it examined and reviewed the medical history of only a small subgroup of people. The majority of these people had no allergic symptoms, despite the high prevalence of antibodies. As these people were only selected from two sites, and were not a randomly selected sample of all workers tested, the possibility of selection bias can't be ruled out.

Another important limitation is that this type of study is unable to prove cause and effect. A prospective cohort study would be the best way of assessing whether non-allergic people subsequently develop allergic sensitivity upon working in environments where they are exposed to these enzymes.

It is also likely that the level of exposure for these workers is higher than for the general public using these products. So the implications for the general population are probably minimal.

Another drawback to the research, acknowledged by the authors, is that commercial secrecy limited access to data, preventing them from gaining access to the chemical formulations used.

Nonetheless, should these findings be verified and suggest that these enzymes lead to allergies, further regulation around products containing such enzymes may be required. 

Links To The Headlines

Enzymes used in cleaning products and food 'are potent allergens', warns study. The Guardian, September 22 2016

GM enzymes used in household products 'are potent allergens'. The Daily Mail, September 22 2016

Links To Science

Budnik L, Scheer E, Sherwood Burge P et al. Sensitising effects of genetically modified enzymes used in flavour, fragrance, detergence and pharmaceutical production: cross-sectional study. Published September 21 2016

Categories: NHS Choices

People with 'obesity gene' can still lose weight

Wed, 21/09/2016 - 17:30

"No excuses not to slim as 'fat gene' found not to affect ability to lose weight," reports The Daily Telegraph.

It is one of several news outlets to report on research suggesting people who put on weight easily because of a genetic variant do just as well as other people on weight loss interventions such as diet, exercise and drug-based treatments.

A variant of the FTO gene is one of 97 potential gene variants thought to influence people's chances of being overweight or obese. The FTO variant has been shown to have the strongest association with obesity. People with two copies of the variant weigh on average 3kg more and are 1.7 times more likely to be obese.

The study included 9,563 people from eight separate studies of weight loss programmes involving various combinations of diet, exercise, medication and behaviour change treatment.

Researchers looked at how people with an obesity-promoting variant of the FTO gene fared, either on treatment or in control groups, compared to those without the gene variant. They also looked to see whether people with the gene variant responded better to one type of weight loss treatment than another.

They concluded that, while FTO variant genes make it more likely that people will be overweight, it doesn't affect their ability to lose weight through diet and exercise or other treatment. In addition, no one treatment or intervention worked better for them than any other.

The researchers also suggest there would be little point in screening overweight people for the FTO gene variant, as this would not predict the success of their treatment programmes.

Where did the story come from?

The study was carried out by researchers from 25 different international institutions, led by Newcastle University in the UK, and was funded by the Alfred Deakin postdoctoral research fellowship and the UK Medical Research Council.

The study was published in the peer-reviewed British Medical Journal (BMJ) on an open-access basis meaning it is free to read online.

While The Guardian gave a good overview of the science behind the study, the Mail Online confused the ability to lose weight with the chances of gaining weight and its headline seemed to take pleasure in pointing a finger at obese people: "It's not in the genes! You can't blame your DNA for piling on the pounds".

Although the Mail's story later made clear the FTO gene variant does in fact increase the chances of "piling on the pounds", the tone is set by the headline.

The Telegraph decided the research showed there were "No excuses not to slim" and that carriers of the gene variant will be "bang out of excuses" for their weight.

What kind of research was this?

This was a systematic review and meta-analysis of randomised controlled trials. This type of study is sometimes called the "gold standard" for research, because it pools data from the best quality studies that compare how people respond to different types of treatment. However, it is reliant on the quality of the underlying studies.

What did the research involve?

Researchers looked for all randomised controlled studies of weight loss treatments carried out in overweight or obese adults, which had information about people's FTO genotype. They asked the study authors to provide data on the individual patients, not just the summarised published data. They then pooled the data from the studies, and ran a number of tests for potential bias or confounding factors.

They calculated whether there was a difference in the measures of weight of people with and without the FTO variant; whether treatment response varied by FTO variant, and whether this was affected by factors including age, sex, initial weight and ethnic background.

They included studies with measures of body mass index (BMI), waist circumference and body weight. They excluded three studies which they'd wanted to include, but where they could not get individual patient data. They searched only for studies published with an English language abstract, which means some foreign language studies might have been missed.

What were the basic results?

The researchers found no significant differences between weight loss outcomes in people with and without the FTP variant, regardless of the type of weight loss treatment used. This applied to all measures of weight loss – waist circumference, BMI and body weight – and to all lengths of treatment and study follow up (from eight weeks to three years).

How did the researchers interpret the results?

The researchers said their results showed that "people who carry obesity risk FTO genotypes respond equally well to weight loss treatment."

They say their findings show the genetic predisposition to obesity associated with the FTO variant "can be at least partly counteracted through dietary, exercise, or drug-based weight loss interventions."


There's been a lot of interest in how our genes interact with our environment and lifestyle when it comes to body weight.

The discovery that certain gene variants are associated with a higher chance of becoming overweight or obese has been taken by some to mean that people's weight is genetically determined. That could lead to people fearing there's no point in them trying to lose weight, but this study shows that isn't the case.

The results sound like good news for anyone who wants to lose weight for health reasons. Diet and exercise programmes can help, and even if you carry the "obesity gene" variant, these results suggest you have as much chance of success as anyone else.

This is particularly important for the increasing numbers of adults who are overweight or obese. According to the 2014 Health Survey for England, 62% of adults were either overweight or obese and 23% were obese.

There are a few points to bear in mind:

  • the summary included only eight studies, with a relatively low number of participants overall for a meta-analysis
  • the study only looked at one type of genetic variant, although this was the one most strongly linked to obesity. It's possible that other genetic variants or combinations do have an effect on weight loss
  • the majority of the studies were carried out in white people from Europe or the US, so we don't have a clear picture from this study whether ethnic background affects outcomes differently
  • due to the short follow up of some studies, we can't tell whether the genetic variant might affect the chances of putting weight back on after initial weight loss

For information about how to reach and maintain a healthy weight with diet and exercise, see our 12 week weight loss guide.

Links To The Headlines

Obesity gene no barrier to weight loss, study shows. The Guardian, September 21 2016

It's NOT in the genes! You can't blame your DNA for piling on the pounds, scientists reveal. The Daily Mail, September 21 2016

No excuses not to slim as 'fat gene' found not to affect ability to lose weight. The Daily Telegraph, September 21 2016



Links To Science

Livingstone K, Celis-Morales C, Papandonatos D. FTO genotype and weight loss: systematic review and meta-analysis of 9563 individual participant data from eight randomised controlled trials. British Medical Journal. Published September 20 2016

Categories: NHS Choices

NICE issues new guidelines on sexting in teens

Tue, 20/09/2016 - 18:28

"An NHS watchdog has issued advice about sexting to help professionals spot the difference between 'normal' sexual experimentation and harmful sexual behaviour among children and teens," BBC News reports.

The National Institute for Health and Care Excellence (NICE) has issued new guidelines on what is known as harmful sexual behaviour. As well as sexting (sending sexually explicit pictures or messages via smartphone) it also includes other age inappropriate sexual behaviour such as watching extreme pornography or making inappropriate remarks.

The NICE guidance, published online today, focuses on children and young people who are the sole offenders of harmful sexual activities, directed either towards themselves or others, rather than child sexual exploitation, peer-on-peer or gang-related sexual violence.

NICE suggests inappropriate sexual behaviour, including sexting, is often an expression of other underlying problems and should be addressed early.


Need for Guidelines

The guidelines have arisen from a need to ensure problems related to harmful sexual behaviour do not escalate and lead to children being charged with sexual offences. It also aims to ensure children do not get referred to specialist services unnecessarily.

Not much is known about children and young people who display harmful sexual behaviour that has not reached a level regarded as criminal. The response to these behaviours is difficult as there is a lack of understanding about where in the social care system these children should be directed, making effective responses challenging.

Evidence suggests that for children or young people, displaying sexualised behaviour can be an expression of other underlying problems. Early assessments without involving specialist harmful sexual behaviour services can help, however there is limited evidence of effective approaches to combat harmful sexual behaviour.

The guidelines are targeted at a range of people, including social workers, child and adolescent mental health services, youth offending teams, schools, primary care workers and people committing harmful sexual behaviour, their families and the public.



NICE guidelines recommend that schools have a named safeguarding lead and that there is more support and collaboration between services. Key people such as teachers, social workers and doctors should judge how appropriate the sexual behaviour is for the age of the child or young person.

Indicators of possible problems include: using sexualised language such as adult slang words to talk about sex, sexualised behaviour such as sexting or sending sexual images using online or mobile technology, or viewing pornography inappropriate for age or developmental status.

Inappropriate behaviour can be identified using tools such as the Brook Sexual Behaviours Traffic Light Tool, which helps identify the seriousness of the behaviour using a traffic light system. Early assessment is then recommended to see if the child has any unmet needs that can be addressed with universal services, such as at school, health visitors or the GPs. They also recommend considering involving the child's family before referral or any intervention.

If harmful sexual behaviour is displayed, the guidelines recommend referring children to harmful sexual behaviour services, child protection services and the criminal justice system, if necessary.

On referral, a single lead point of contact should be identified to make sure there are no unnecessary assessments or repetitions in services. The lead role should be agreed by the multi-agency team and could be from the child and adolescent mental health service, children's social services or the voluntary sector such as Barnardo's or the NSPCC.

If you are concerned that a child in your care may be engaging in harmful sexual behaviour a useful first step would be to talk to a health or social care professional who has been in contact with the child, such as their teacher, social worker or GP. 

Links To The Headlines

NHS watchdog issues sexting advice. BBC News, September 20 2016

Sexting: treating children as 'mini sex offenders' could make things worse. The Daily Telegraph, September 20 2016

Children caught sexting should be sent to social workers and psychiatrists, say health chiefs. Mail Online, September 20 2016

Don't ignore child sexting, teachers told. The Times, September 20 2016

Categories: NHS Choices

Cuddling a kitten almost certainly won't kill you

Tue, 20/09/2016 - 15:28

"Cuddling kittens can kill you," warns The Telegraph in one of the more alarming headlines to appear in the national press for some time.

But cat lovers can relax – deaths and serious illness from "killer kittens" with so-called cat scratch disease (CSD) are exceedingly rare.

In fact, the study on which this and other headlines are based did not report any deaths, although it estimated 500 people are admitted to hospital in the US each year with the disease.

CSD is caused by bacteria spread among cats by fleas, which can infect humans through scratches and possibly bites from cats.

It causes swollen lymph glands. Some people get more serious infections, leading to inflammation of the brain or the inner lining of the heart.

The study found CSD was most common among children and in southern areas of the US where cats are more likely to be flea-infected. However, it can happen "wherever cats and their fleas are found", the researchers report.

Commonsense measures, such as getting cats treated for fleas and washing hands after handling cats, are likely to reduce the risk of contracting CSD.

And while people with weakened immune systems do need to take extra care around animals, the risk of most people being killed by a kitten is up there with being killed by a falling meteoroid – technically possible, but not something to keep you up at night.

Where did the story come from?

The study was carried out by researchers from the US Centers for Disease Control and Emory University, and was funded by the US Centers for Disease Control

It was published in the peer-reviewed journal Emerging Infectious Disease on an open access basis, so it's free to read online.

The Telegraph, Mail Online and Metro reported the study with glee, stating that the disease was "potentially fatal".

While this is true, CSD is usually mild and only about 4 in 100 people who contract it need to be admitted to hospital.

Oddly, Mail Online warned about a "rare bacteria" in cats' mouths called Capnocytophaga canimorsus. That bacterium is more commonly associated with dog bites and does not cause CSD, which is caused by the bacterium Bartonella henselae.

The Metro doesn't seem to take the study entirely seriously, complaining of "killjoy doctors" telling us "now we're not allowed to cuddle kittens", concluding that "we're getting tired of this planet". 

What kind of research was this?

This epidemiological study used records from a US insurance companies claims database to look at how many people had been diagnosed with CSD between 2005 and 2013.

Database studies can show overall trends, but can't explain what's behind the trends. They are only as good as the accuracy of the records held in the database.

What did the research involve?

Researchers took all records of people diagnosed with CSD who made claims for treatment paid for by insurance companies between 2005 and 2013.

They compared how the numbers changed over time, and looked at which groups of people were most affected, whereabouts, and what proportion had to be treated in hospital.

They summarised the findings to give an overall picture of the disease in the US.

Importantly, the database only looked at people aged under 65 who were in employee-sponsored private health insurance schemes.

The figures don't tell us about people over 65 or those with no private health insurance. The figures only include people in the US, so they also don't tell us how common CSD is in the UK.

What were the basic results?

On average, there were 4.5 outpatient cases of CSD for every 100,000 people every year, and 0.19 cases per 100,000 people each year where patients needed to be admitted to hospital. 

Children aged five to nine years were more likely to get the disease, which was also more common among women than men. Older women aged 60 to 64 were most likely to get the disease.

The number of cases fell over the years by about 1 per 100,000 from the start to the end of the study period.

However, the numbers being admitted to hospital as outpatients stayed the same.

The disease was more common in the south of the US, and the researchers found peaks during the autumn and in January.

How did the researchers interpret the results?

The researchers say CSD is "mostly preventable", but "causes a substantial burden of disease nationwide and disproportionately affects children".

They call for "comprehensive flea control for cats", saying that people should wash their hands after handling cats to remove traces of flea faeces that could infect any breaks in the skin.

They say educational efforts should be directed at cat owners, especially those with children in the household or where someone has an immune system deficiency.


The media headlines may sound ridiculous, but taking basic hygiene precautions when handling any animals, no matter how cute they are, is sensible advice.

Although CSD is unusual and does not often cause serious illness, it can be a threat to people with a compromised immune system – for example, those with HIV or taking immunosuppressant drugs.

Scratches and bites from any animal can get infected by bacteria carried by the animal. Even if it's not the bacteria that causes CSD, infected wounds can be painful and cause illness.

It makes sense to teach children in particular how to interact safely with animals to avoid scratches and bites that could get infected.

If the incidence of CSD was the same in the UK, there would be 2,907 outpatient cases in the UK each year.

But this study doesn't tell us whether the incidence is the same here as the US. As the incidence varies between different states in the US, the chances are it will be different in the UK.

There are also some questions about the validity of the figures – we don't know whether all the cases had been positively diagnosed using bacteria analysis, or whether they were probable diagnoses. It's also possible some cases were misdiagnosed as other illnesses.

While cat owners can be reassured that their pets are unlikely to kill them, everyone should know about hand washing and safety around pets.  

Links To The Headlines

Cuddling kittens can kill you, warn scientists. The Telegraph, September 19 2016

Cuddling your kitten could KILL you: CDC warns adorable felines carry deadly bacteria that causes brain swelling and heart infection. Mail Online, September 19 2016

Snuggling and kissing kittens could actually kill you, scientists have warned. Metro, September 19 2016

Links To Science

Nelson CA, Saha S, Mead PS. Cat-Scratch Disease in the United States, 2005–2013. Emerging Infectious Diseases. Published online September 19 2016

Categories: NHS Choices

Contraceptive pills not proven to protect against the flu

Mon, 19/09/2016 - 17:30

"How taking the pill could protect you from the flu," was the curious headline on a recent Mail Online article.

The equally curious animal study involved female mice who had their ovaries surgically removed – half were then given progesterone implants, half weren't.

Progesterone is one of the active ingredients in the combined pill and the main ingredient in the progestogen-only pill.

Researchers administered a lethal dose of flu virus directly into the mouse's nose. Those who had the progesterone implants survived about two days longer.

Examining the lung tissue suggested that progesterone hormone may be needed for cell repair processes after lung infection or damage.

Neither the species, the fatal flu dose given directly into the nose, or the hormone scenario are directly applicable to humans.

So despite the media latching onto contraception, this study provides no evidence that women taking progestogen-containing contraception have added protection against flu or other infections.

Practicing good hygiene, for example, frequent hand washing and always putting used tissues in a bin, can help prevent a flu infection. Those groups particularly vulnerable to the harmful effects of the flu should make sure they get their annual flu jab.


Where did the story come from?

The study was carried out by researchers from The Johns Hopkins Bloomberg School of Public Health and School of Medicine. The study was funded by grants from the National Institutes of Health, National Institute of Allergy and Infectious Diseases.

The study was published in the peer-reviewed scientific journal PLOS Pathogens.

The study is open-access so can be read online or downloaded for free.

The Mail and The Daily Telegraph's coverage didn't mention the study involved mice until quite far down in their articles. Both say that contraception may be protective – which hasn't been demonstrated at all as these mice had had their natural hormone depleted. If anything, this was more like a test of hormone replacement therapy (HRT) than contraception.

The Mail also reports: "Contraception helps body keep hold of virus-fighting hormones" which isn't correct. This wasn't contraception to help the body "keep hold of" anything; it was hormone replacement. Also, progesterone wasn't directly fighting the virus – it seemed to be needed for normal cell repair processes.


What kind of research was this?

This was an animal study that aimed to see whether artificial progesterone hormones confer protection against potentially lethal flu disease in mice.

All contraceptive hormones taken by women contain some form of artificial progesterone (progestogen) – either in combination with oestrogen as in the combined contraceptive pill ("the pill") or progestogen alone, such as in the "mini pill", injections or implants.

The researchers say previous research suggested progesterone may give some protection against infections of the reproductive tract. Their new study aimed to look at possible protection against respiratory tract infections.

Animal studies are useful for testing theories to see how things might work in humans, but we do not have identical biology.


What did the research involve?

The research involved young female mice (7-8 weeks old) who were housed in standard conditions. A couple of weeks later they had an operation to remove their ovaries. After recovery they were assigned to receive implants under their skin containing either inactive placebo or 15mg of progesterone – which was released at a steady dose over the course of a month.

They were then inoculated via the nose with either placebo or with an influenza virus (H1N1), at a dose lethal for these animals.

They examined whether the mice developed signs of illness – shortness of breath, hair standing on end, hunched posture or absence of an escape response. They also examined samples of blood and lung tissue to look at the make-up of inflammatory cells.


What were the basic results?

The researchers found that the mice with progesterone implants had some protection against flu infection and related lung damage. They died after 11.1 days compared to 9.5 days for the mice who didn't have progesterone implants.

However, progesterone had no effect on blood levels of the virus, suggesting it didn't make them more resistant to infection. Comparing body temperatures though, they found that those treated with progesterone were less likely to have hypothermia after getting flu.

They also had less lung inflammation and damage. Further analysis of lung tissue showed the progesterone mice had greater cell proliferation, reduced protein leakage into the airways, and other findings suggestive of a "repair environment" in the lungs.

The researchers further confirmed that giving a cellular growth factor to the mice lacking progesterone also improved their outcomes following flu infection. 


How did the researchers interpret the results?

The researchers conclude that the progesterone hormone is an essential factor in mediating the production of a cellular growth factor involved in the repair of lung tissue following infection.



These are interesting scientific findings but they have limited implications.

Animal studies are useful for giving an indication of how biological processes may work in humans but we're not identical. So the scenarios tested here – the progesterone, or the flu injection – can't be taken as representative of real-life in humans.

For one thing all the mice had surgery to remove their ovaries before being infected. It makes sense that the mice that had been given some additional recovery boost in the form of hormone replacement may have been in a better health state than those left hormone depleted.

They were also directly inoculated through the nose with a flu dose that has previously been demonstrated to be lethal in these animals, and the animals did die. It's just those with progesterone survived about an extra two days.

The findings do suggest the progesterone hormone may have various roles in female health – also here seeming to improve lung cellular repair. However, since most women have the progesterone hormone naturally in their bodies this doesn't mean a great deal.

We can't leap to saying that women who take progestogen-containing contraception hormones have added protection against infection, or are less likely to get flu. This certainly hasn't been tested.

To reduce your risk of getting flu or spreading it to other people, you should always:

  • make sure you wash your hands regularly with soap and warm water
  • clean surfaces such as your keyboard, telephone and door handles regularly to get rid of germs
  • use tissues to cover your mouth and nose when you cough or sneeze
  • put used tissues in a bin as soon as possible

A flu vaccine is available for free on the NHS for:

  • anyone aged 65 and over
  • pregnant women
  • anyone who is very overweight (with a body mass index over 40)
  • children and adults with an underlying health condition (particularly long-term heart or lung disease)
  • children and adults with weakened immune systems

Your GP can advise you about whether you require the annual flu jab. 

Links To The Headlines

Common contraceptive hormone could protect women from flu. The Daily Telegraph, September 16 2016

How taking the PILL could protect you from the flu: Contraception helps body keep hold of virus-fighting hormones. Mail Online, September 16 2016

Links To Science

Hall OJ, Limjunyawong N, Vermillion MS, et al. Progesterone-Based Therapy Protects Against Influenza by Promoting Lung Repair and Recovery in Females. PLOS Pathogens. Published online September 15 2016

Categories: NHS Choices

Women dying needlessly due to not attending cervical screening

Fri, 16/09/2016 - 17:30

"The lives of hundreds more cervical cancer patients could be saved if all those eligible went for screening," BBC News reports.

An analysis estimates an additional 347 deaths per year in England could be prevented if all eligible women attended cervical screening.

The NHS Cervical Screening Programme was set up to prevent deaths from cervical cancer, and women aged 25-64 are invited to attend regular appointments (depending on age, between every three to five years).

The analysis looked at screening history for more than 11,000 women in England diagnosed with cervical cancer, and matched controls without cancer. The study aimed to look at the potential impact of screening on diagnoses and deaths from cervical cancer.

It found there would be an estimated four to five times more deaths from cervical cancer in women over 35 if no screening existed. However, if all eligible women attended screening regularly there could be even greater benefit – further reducing deaths by half in women 35 to 49, and by two-thirds in women 50 to 64.

This translates into an extra 347 lives per year saved by screening. If cervical cancer is diagnosed at an early stage then the prospects of a complete cure are good.

It could well be the case that the issue of cervical cancer had dropped off the radar for many women since interest previously spiked after the death of reality star Jade Goody in 2009.  

These results may suggest that more now needs to be done to encourage uptake by all eligible women. 


Where did the story come from?

The study was carried out by researchers from the Centre for Cancer Prevention, Wolfson Institute of Preventive Medicine and was funded by Cancer Research UK. The authors declared no conflict of interest.

The study was published in the peer-reviewed medical journal British Journal of Cancer. It is open-access so you can read it for free online.

The UK media reported the story accurately. The Guardian included a statement from Nicola Smith, a senior health information officer at Cancer Research UK, pointing out that cervical screening wasn't just an issue for younger women. "Older women may not think this type of screening is relevant to them, but while cervical cancer is unusual in that it affects women at younger ages than most cancers, older women also develop the disease".


What kind of research was this?

This was a population-based case-control study. It compared screening attendance between women diagnosed with cervical cancer compared to controls without cancer.

This is the most suitable type of study for comparing the past behaviours and activities of people who have gone on to get the disease or not.

The study used data that had already been recorded before women did or did not get cervical cancer which removes the possibility of recall bias. However, this type of study still cannot prove that screening leads to prevention of cancer or death, as other confounding lifestyle factors may be involved in both a woman's likelihood of attending screening and her risk of cancer. But it is useful for looking at the possible impact of screening across a whole population, rather than just how it affects an individual.


What did the research involve?

Researchers used data from the Audit of Invasive Cervical Cancers (NHS Cervical Screening Programme, 2006), which was a population-based case-control study in England that is thought to include around 90% of all cervical cancers.

Cases were women aged 25-79 who had cervical cancer diagnosed in England between 2007 and 2013. Two age-matched comparison women were chosen for each, who did not have cervical cancer and had not had a hysterectomy.

Screening data was taken from routine records and included all NHS smears taken in the UK since 1988.

The odds of developing cancer for women regularly or irregularly screened were compared with women not screened in the past 15 years.

Cancer deaths within five years of cervical cancer diagnosis were analysed.


What were the basic results?

A total of 11,619 women were diagnosed with cervical cancer. More than a third of women were diagnosed between 35 and 49 years, and over a third were diagnosed with a small cancer still confined to the cervix (stage 1A).

Regular screening was associated with a 67% reduction in the odds of women (aged 35 to 64) being diagnosed with this early stage cancer, and a 95% reduced risk of being diagnosed with advanced stage 3 cancer that's spread into the pelvis. 

In the absence of screening, it was estimated there would be more than double the number of cancers diagnosed in women aged 25 to 79 (relative risk [RR] 2.53, 95% confidence interval [CI] 2.39 to 2.68). If all eligible women were regularly screened, there would be around a third fewer cancers (RR 0.66, 95% CI 0.64 to 0.67).

Changing screening practices would have the greatest impact on women aged 50 to 64. Cancer rates would be about four times higher with no screening (RR 4.15, 95% CI 3.63 to 4.74). If everyone was regularly screened, rates in this age group would be less than half the current rate (RR 0.48, 95% CI 0.46 to 0.51).

In the absence of screening, cervical cancer deaths would be:

  • four times higher for women aged 35 to 49 (RR 4.13, 95% CI 3.59 to 4.75)
  • five times higher for women aged 50 to 64 years (RR 5.30, 95% CI 4.36 to 6.44)

If all women were regularly screened, mortality would be:

  • less than half what it currently is for women aged 35 to 49 at diagnosis (RR 0.42, 95% CI 0.38 to 0.47)
  • reduced by two-thirds for women aged 50 to 64 (RR 0.35, 95% CI 0.33 to 0.37) 
How did the researchers interpret the results?

The researchers concluded they have shown "screening has an even larger impact on cervical cancer mortality than it has on [cancer diagnosis rates], and that if everyone attended screening regularly, 83% of cervical cancer deaths could be prevented, compared with 70% with current screening."

They also said that "these results are encouraging and should be used to promote, among women, regular attendance to screening and, among policy makers, the implementation of organised screening programmes in areas not yet covered."

They conclude "a further 347 deaths per year could be prevented if everyone attended screening regularly between ages 25 and 64 years".



More than 11,000 records were analysed in this study investigating the association between cervical cancer screening and cervical cancer rates and related deaths. The strength of this study is the vast number of women included and the use of screening data going back up to 15 years.

The findings suggest that screening currently prevents thousands of cervical cancers each year. However, if uptake were improved further and all eligible women attended regular screening, even more cancers could be avoided and lives saved.

One note of caution though is that the study still can't prove that cervical cancer screening is wholly responsible for any differences in cancer diagnoses or mortality rates between cases and controls. There may be important lifestyle factors that are associated both with risk of cervical cancer and likelihood of attending screening.

Women who smoke are at increased risk of cervical cancer, as are women who have unprotected sex with multiple partners (increasing their risk of acquiring the HPV virus that causes the cancer). It is possible that some women with these risk factors could also be less likely to follow other healthy lifestyle practices, such as attending regular screening.  

Nevertheless, the study suggests that uptake of the cervical cancer screening programme could be improved. To do this, health practitioners and policy makers could further promote uptake among women aged 25 to 64.

If you are unsure if or when you should attend a cervical screening appointment then contact your GP for advice.  

Links To The Headlines

Cervical screening 'could save hundreds more lives'. BBC News, September 16 2016

Full uptake of cervical cancer screening could save hundreds of lives. The Guardian, September 16 2016

Why you should NEVER miss a smear test: Cervical screening 'saves 2,000 lives a year'. Mail Online, September 16 2016

Links To Science

Landy R. Pesola F, Castañón A, Sasieni P. Impact of cervical screening on cervical cancer mortality: estimation using stage-specific results from a nested case–control study. British Journal of Cancer. Published online September 15 2016

Categories: NHS Choices

Could fertility breakthrough lead to babies with no mothers?

Thu, 15/09/2016 - 18:30

"Fertility breakthrough means babies could be conceived from skin cells – so men can have babies with each other," is the excitable headline in the Daily Mirror.

But the research in the news is at an early stage – and was in mice. Despite reporting to the contrary, the study involved female eggs, not skin cells.

This experimental UK research involved mice whose eggs were tricked into starting to develop and divide as if they had been fertilised.

These "fake" embryos were then injected with sperm and implanted into female mice. There was an up to 24% success rate producing healthy offspring.

However, this is very early-stage research and it is important that we do not speculate about its potential implications at this point.

As the authors acknowledge, their work only demonstrates a principle – there are major barriers to overcome before reproduction in humans without egg cells would be a technical possibility, not to mention the ethical questions. Just because you can do something doesn't necessarily mean you should.

Moreover, mice are not human and this may not be an appropriate model on which to base predictions of how the process happens in humans.

This study was arguably the subject of spin at multiple levels – the university press office, comments made by the study's authors, and the media itself.

Find out more about spin in medical reporting.

Where did the story come from?

The study was carried out by researchers from the University of Bath in the UK, and the Institute for Toxicology and Experimental Medicine ITEM and the University of Regensburg in Germany.

It was funded by the UK Medical Research Council. The authors declared no conflicts of interest.

The study was published in the peer-reviewed journal, Nature Communications. It is open access, so you can read it for free online.

For the most part, the media coverage around the topic was accurate, stressing that the work is in its early stages.

But headline writers decided to pick up the hype ball and run with it. Many headlines talked about "motherless babies", which did not acknowledge that the study still relied on eggs taken from a female.

The Daily Mirror speculated about men having babies with each other, while the Daily Mail imagined a world without mothers. All of these concepts are pretty far removed from a small study involving mice.

What kind of research was this?

This mouse study aimed to look at the possibility of tricking sperm into believing they were fertilising normal eggs.

Embryologists first observed fertilisation in the late 19th century, and it has long since been assumed that only an egg cell fertilised with a sperm cell can result in a live mammalian birth.

The exact mechanisms of fertilisation – what happens when a sperm fuses with an egg – are not well known, and researchers aim to understand these processes more.

Animal studies are often used in the early stages of research to see how biological processes may happen in humans.

But we are not identical to animals, and the mechanisms in humans may differ and need to be tested in other ways.

What did the research involve?

This complex laboratory study used mice to observe if healthy offspring could be produced using a technique that bypasses the usual processes of fertilising an egg cell with a sperm.

Scientists used chemicals to trick mouse eggs into developing as though they had been fertilised.

These unusual embryos, known as parthenogenotes, were in the stage of cell division and contained a half set of chromosomes. These embryos usually die after a few days, as they do not have the correct programming.

Sperm was then injected into the embryos and they were transferred into female mice. The success of the process was determined by the ability of the mice to produce healthy offspring.

What were the basic results?

After injecting the sperm into the embryos, some were observed to develop normally and on transfer into female mice grew into apparently healthy mice pups.

In total, 30 pups were produced with a success rate of up to 24%, depending on the stage when the embryo cell cycle was injected with sperm.

Some pups went on to have offspring of their own, and some of these also had pups.

The researchers further describe in detail the cellular processes that took place when the embryo cells were injected with sperm.   

How did the researchers interpret the results?

The authors say the ability of embryos to reprogramme sperm in the process of cell division (mitosis) blurs functional distinctions between the different cell lines: sex cells, body cells and early-stage embryonic cells.

They further suggest that their work "calls into question the argument that parthenogenotes do not have the potential for full-term development and are accordingly a more acceptable source of human embryonic stem cells". 


This experimental study in mice shows that normal egg fertilisation is not the only way of maturing a sperm into a form needed to create all the tissues in the body.

The researchers suggest that if it is possible to produce healthy mice babies by injecting sperm into pseudo-embryos, it might one day be possible to repeat the process in humans using cells that are not from eggs.

They hope to extend the research to study the potential for skin cells to replace eggs in the future.

However, as the authors acknowledge, this early work only demonstrates a principle – there are major barriers to overcome before reproduction in humans without egg cells would be a technical possibility, aside from ethical questions.

Mice are not human – this means this may not be an appropriate model on which to base predictions of how the process happens in humans.

There are many more research stages to undergo to further understand these findings and their possible implications.

One final point is that if you ever see a news article with a question mark in the headline – like this one: "Could fertility breakthrough lead to babies with no mothers?" – the answer is almost always "We don't know". 

Links To The Headlines

Fertility breakthrough means babies could be conceived from skin cells – so men can have babies with each other. Daily Mirror, September 13 2016

Motherless babies possible as scientists create live offspring without need for female egg. The Daily Telegraph, September 13 2016

‘Motherless’ babies could be created from skin cells and sperm, scientists claim. Metro, September 13 2016

Skin cells might be used instead of eggs to make embryos, scientists say. The Guardian, September 13 2016

The babies with no mothers: Scientists discover how to make embryos from skin cells instead of eggs, making women redundant. Daily Mail, September 13 2016

Links To Science

Suzuki T, Asami M, Hoffmann M, et al. Mice produced by mitotic reprogramming of sperm injected into haploid parthenogenotes. Nature Communications. Published online September 13 2016

Categories: NHS Choices

Invasive early prostate cancer treatments not always needed

Thu, 15/09/2016 - 17:30

"Closely monitoring prostate cancer offers just as good a chance of survival as harsh and invasive treatments," The Daily Telegraph reports.

Researchers found invasive treatments for early stage prostate cancer, such as surgery, didn't help people live any longer when compared to active surveillance.

Active surveillance means a patient receives no immediate treatment, but instead, is given regular tests to check for signs of cancer progression. Some cases of prostate cancer can spread quickly. Many others never actually spread out of the prostate.

The headlines are actually based on two studies. The first looked at whether there were differences between survival outcomes if men received active surveillance, surgery or chemotherapy.

Survival rates were the same for all three groups; a 1% mortality rate during a 10 year follow up period. That said, men who had active monitoring of their cancer were more likely to see the cancer spread to other parts of the body, and half of them went on to have surgery or radiotherapy during the 10-year follow up.

However, a second study of the same patients showed they were much less likely to have side effects of treatment, especially sexual problems and urinary incontinence, than men who had surgery or radiotherapy at the study's start.

These results don't apply to men who are diagnosed with advanced prostate cancer.

It is important to discuss all possible care options with the doctor or team in charge of your care. Sometimes choosing not to treat a condition immediately is the best option.


Where did the story come from?

The research was carried out by researchers from 13 UK universities and hospitals, led by the Universities of Oxford and Bristol, and was funded by the National Institute for Health Research. The studies were published in the peer-reviewed New England Journal of Medicine.

Most of the media reports focused on survival rates of the different treatments, although The Guardian and BBC News also included information about the chances of side effects with surgery or radiotherapy.

The general tone of the reporting was accurate in pointing out that active surveillance could well be the best initial option for men with early stage prostate cancer.


What kind of research was this?

These two studies were randomised controlled trials, which is the best type of study for comparing the results of different treatments.

However, in a study of such different treatments, it would not be possible to "blind" people to whether they had surgery, radiotherapy or active monitoring of the disease, so it's not a double blind study.

Researchers wanted to know how the type of treatment affected people's chances of dying from prostate cancer, the chances of cancer spreading, and the effects on sexual function, urinary and bowel function and their overall quality of life.


What did the research involve?

Researchers invited 82,429 men to have screening with a prostate-specific antigen (PSA) test. The test can check to see if the prostate is enlarged, but as the prostate usually grows larger as men grow older, a diagnosis of prostate cancer usually needs to be confirmed with a biopsy.

Of the 2,664 men who were subsequently diagnosed with localised prostate cancer, 1,643 agreed to take part in the study. These men were randomly divided into three groups:

  • active surveillance (also known as active monitoring) of their cancer
  • surgery to remove the prostate gland (prostatectomy)
  • radiotherapy and hormone therapy intended to destroy the cancer and prevent it growing

They were followed up for an average of 10 years, during which time they were sent questionnaires about their symptoms and quality of life. The researchers then compared what had happened to men in each treatment group, reporting separately on the mortality results and the quality of life results.

Men who had active monitoring had their PSA level checked every three months in the first year, then every six to 12 months after that. If the PSA level increased by more than half, they and their doctors considered whether to continue with active surveillance or have surgery or radiotherapy.

The two studies of treatment are part of a larger study looking at the effects of PSA screening. The 2,664 men diagnosed with localised prostate cancer had all had PSA tests, without showing any signs of cancer, as part of this bigger study.

At present, men can ask their GP for a PSA test, but it's not offered routinely, because there's no good evidence that PSA screening reduces the number of men who die from prostate cancer.


What were the basic results?

The main finding was that about 1 in 100 men died of prostate cancer during the 10 years of follow-up, regardless of the type of treatment they'd been assigned to. Deaths from other causes were the same in all three groups, at 9%.

However, 53% of the men who'd started with active monitoring had switched to surgery or radiotherapy by the end of the study, and 20.5% had showed signs of cancer progression. Only about 8% of men who had surgery or radiotherapy showed signs of cancer progression, although it's difficult to compare this between the groups.

Men who had a prostatectomy were much more likely to have had problems with sexual function (including inability to get an erection firm enough for sex) or to have had urinary incontinence.

Only 12% of men who'd had prostatectomy were able to have penetrative sex six months after the start of the study, compared to 22% who'd had radiotherapy and 52% who'd had active monitoring. Almost half (46%) of men who'd had surgery needed to use absorbent pads for urinary incontinence at six months, compared to 5% and 4% of men who'd had radiotherapy or active surveillance.

Although these figures improved over time, men in the surgery group continued to have worse outcomes in these areas than the other groups throughout the study. Bowel function deteriorated somewhat among men who'd had radiotherapy, but recovered later.

Men's overall quality of life was roughly the same across the three treatment groups, and no group had more anxiety or depression than another.


How did the researchers interpret the results?

The researchers say their findings give men useful information to consider their options: "Men with newly diagnosed, localised prostate cancer need to consider the critical trade-off between the short-term and long-term effects of radical treatments on urinary, bowel and sexual function and the higher risks of disease progression with active monitoring."

Importantly, they warn that "longer term survival data will be crucial" to find out whether the higher rates of cancer progression for men having active monitoring translate into shorter length of life beyond the first 10 years after diagnosis.



Decisions about treatment for prostate cancer are fraught with difficulty, especially in the early stages. Because many prostate cancers grow very slowly, some men don't need treatment and will never be bothered by their cancer.

However, some cancers grow and spread around the body, and can be fatal if not treated. Until now, there's been insufficient good information to help men decide whether to choose surgery, radiotherapy or active monitoring.

These studies give us the best evidence yet to compare the results of the three most commonly-used treatments. The results don't tell us that one treatment is better for everyone, but mean that men can compare and discuss their options with doctors and their families, before making a choice that reflects their own priorities and values.

Some men will want to have surgery or radiotherapy straight away to avoid the risk of the cancer progressing, and will accept the chance of side effects. Others will prefer to wait and have their disease monitored, in the hope of avoiding side effects.

Men may find it reassuring that few men died of prostate cancer during the study, and that choice of treatment didn't affect their survival chances 10 years after diagnosis.

There are some points to be aware of, however:

  • 10 years may be too short a time to properly assess the effects of treatment on length of life.
  • Men who had treatment later, after initial active monitoring, may do worse over the long term.
  • This research is ongoing so we will have more information in future.
  • Treatments for prostate cancer are changing all the time, and these studies represent treatments carried out 10 years ago. Newer treatments, such as implanting radioactive seeds into the prostate, were not included in the study.
  • A proportion of each group did not have the treatment allocated to them.
  • Few men in the studies were from African Caribbean backgrounds, which may mean the results don't apply to that group.

However, these studies were large, randomised controlled trials, carefully designed and carried out, with a high level of successful follow-up. They represent an important advance in doctors' understanding of the comparative effects of common treatment options for this common cancer.  

Links To The Headlines

Prostate cancer survival rates equally high if you monitor disease rather than having surgery or radiotherapy. The Daily Telegraph, September 15 2016

Why thousands are having needless prostate treatment: Doctors claim regular check-ups are just as good as surgery and radiotherapy. Daily Mail, September 15 2016

Monitoring of prostate cancer as effective as treatment in some cases. The Guardian, September 14 2016

Prostate cancer treatment 'not always needed'. BBC News, September 15 2016

Prostate cancer patients live just as long with NO treatment, experts have revealed. Daily Mirror, September 14 2016

Links To Science

Donovan JL, Hamdy FC, Lane JA, et al. Patient-Reported Outcomes after Monitoring, Surgery, or Radiotherapy for Prostate Cancer. The New England Journal of Medicine. Published online September 14 2016

Hamdy FC, Donovan DL, Lane JA, et al. 10-Year Outcomes after Monitoring, Surgery, or Radiotherapy for Localized Prostate Cancer. The New England Journal of Medicine. Published online September 14 2016

Categories: NHS Choices

E-cigarettes 'help thousands successfully quit smoking'

Wed, 14/09/2016 - 16:30

"The rise in popularity of e-cigarettes in the UK may have resulted in more successful attempts to quit smoking," BBC News reports.

A UK study looking at survey data from England over the past 10 years showed the proportion of successful quit attempts rose in line with the number of smokers using e-cigarettes.

But the number of quit attempts does not seem to be linked to e-cigarette use, and has actually fallen in recent years.

The study, which involved interviews with 170,490 people, can't prove e-cigarettes directly caused the increase in people's successful attempts to quit smoking.

But it does show how trends like e-cigarette use – as well as other factors like the use of other smoking cessation aids, public health campaigns and changes in smoking regulation – may affect smoking rates at a population level.

While research into the safety of e-cigarettes is still ongoing, there's little doubt using these devices is much less harmful than continuing to smoke tobacco.

If you want to stop smoking, evidence shows the best way to do so is to get support, such as counselling, available through NHS stop smoking services.

Other options that can help you quit smoking include nicotine patches, gum and inhalers, as well as medication like varenicline.

Read more about stop smoking treatments.

Where did the story come from?

The study was carried out by researchers from University College London and was funded by Cancer Research UK. 

It was published in the peer-reviewed British Medical Journal (BMJ) on an open access basis, so it is free to read online.

The Guardian gives a good overview of the study, and includes information from a newly published review into the safety and efficacy of e-cigarettes from the Cochrane Collaboration.

The Cochrane review looked at previous studies – not the BMJ study currently hitting the headlines – and concluded: "The quality of the evidence overall is low because it is based on only a small number of studies, although these studies were well conducted. More studies of ECs [electronic cigarettes] are needed."

The Telegraph accurately reported on the study, stating that the long-term safety of e-cigarettes was uncertain.

While this is true, most experts believe they are much less harmful than tobacco. A 2015 evidence review by Public Health England concluded e-cigarettes are "95% less harmful than smoking".

BBC News made a mistake in their reporting of the figures, stating that the study found "the number of smokers who successfully managed to stop smoking increased by just under 1% for every 1% rise in the number of smokers using e-cigarettes".

The actual rise in successful quit attempts was just under 0.1% for each 1% rise in e-cigarette use.

What kind of research was this?

This was a time trend analysis of population trends using data collected from a series of cross-sectional surveys.

It aimed to assess whether changes in the use of e-cigarettes over the years in England is linked to changes in quit attempts, quit rates and the use of other stop smoking services.

This type of study can't prove cause and effect, but it is useful for looking at the potential impact of trends and policies across a whole population, rather than just looking at how they affect individuals.

For example, a trial that looked at whether people were more likely to quit smoking using e-cigarettes can tell us whether e-cigarettes help motivated smokers quit.

But it can't tell you how the growing use of e-cigarettes might affect others – for example, whether people make fewer quit attempts or more young people take up smoking when e-cigarettes are commonly used.

What did the research involve?

Researchers interviewed households chosen as representative of the English population every three months from 2006 to 2015.

Participants were asked about their smoking habits, including e-cigarette use, whether they'd made any attempts to quit in the last year, and what they'd used to help them quit.

After adjusting their figures to take account of possible confounding factors, the researchers calculated the relationship between the number of people using e-cigarettes either recreationally or to quit smoking, and quit attempt rates, successful quit rates and use of other treatments, such as nicotine replacement therapy.

The data came from both the survey itself – the Smoking Toolkit Study – and information from English NHS stop smoking services, which provided data about the number of people using NHS services.

Researchers took account of changes in health policy, such as the change from centralised to local commissioning of stop smoking services, media campaigns encouraging people to stop smoking, the change in minimum age for buying cigarettes from 16 to 18 in 2007, and the smoking ban indoors in public places, also in 2007.

They calculated the percentage change in outcomes – including quit attempts, successful quit attempts and use of prescribed smoking cessation aids – for each 1% rise in use of e-cigarettes over the period.

What were the basic results?

About 23% of people in the study had smoked in the past year. Use of e-cigarettes rose from almost no use in 2006 to 21.3% of smokers at the start of 2015.

Use of e-cigarettes to help quit attempts also rose sharply, especially from 2012, with 35% of people attempting to quit in the first quarter of 2015 saying they used e-cigarettes.

The proportion of successful quit attempts also rose, from 10.6% in 2006 to 18.6% in 2015. Researchers said that looking at the trend over time, this could be represented as a 0.098% increase in success rates for every 1% increase in use of e-cigarettes.

But the proportion of people attempting to quit smoking fell over the study period, from about 45.4% of smokers in 2006 to 31.2% at the end of the study.

Looking at the data over time, the researchers said there was no clear association between the increasing use of e-cigarettes and the decreasing number of quit attempts.

The study also showed that declining use of prescription nicotine replacement therapy (NRT) was linked to the increase in e-cigarette use.

How did the researchers interpret the results?

The researchers say that if the link between changes in e-cigarette use and successful quit attempts is down to cause and effect, then e-cigarette use in 36% of the 2.6 million quit attempts in 2015 may have resulted in 54,288 successful short-term quit attempts.

They say two-thirds of those people are likely to relapse, meaning an additional 18,000 long-term ex-smokers resulting from the use of e-cigarettes in one year.

They also say the decline in quit attempts during the study period needs further investigation, but possible causes include a big drop in spending on public health stop smoking campaigns in 2010, the financial crisis, and the fact smokers have become gradually less sensitive to messages encouraging them to quit.


Stopping smoking remains the best thing you can possibly do for your health. Anything that can help reduce the number of people who smoke is likely to have a good impact on health.

But although this study found e-cigarette use was linked to an increase in successful quit attempts, there are a number of things to be aware of:

  • Attempting to quit with e-cigarettes alone may not be as helpful as attempting to quit using an NHS stop smoking service. Getting support and help for a quit attempt is thought to increase your chances of success fourfold. You can use NHS services and e-cigarettes together if you wish.
  • The study can't prove using e-cigarettes is the direct reason for the improved rate of quit attempts as other confounding factors may have been involved.
  • Some of the study results were surprising – for example, the researchers calculated that the rise in the legal age for smoking from 16 to 18 was associated with a bigger increase in quitting success rates than you'd expect. This casts some doubt over the results.

Questions remain about whether e-cigarettes are really safe. While there's still work to do on this, Public Health England estimates the aids are 95% safer than using tobacco cigarettes.

The important thing if you're a smoker is to give yourself the best possible chance of stopping smoking for good.  

Links To The Headlines

E-cigarettes 'help more smokers quit'. BBC News, September 14 2016

E-cigarettes can help smokers quit, says study. The Guardian, September 13 2016

E-cigarettes helped 18,000 people quit smoking in 2015 but long-term effects still unknown. The Telegraph, September 14 2016

Links To Science

Beard E, West R, Michie S, Brown J. Association between electronic cigarette use and changes in quit attempts, success of quit attempts, use of smoking cessation pharmacotherapy, and use of stop smoking services in England: time series analysis of population trends. BMJ. Published online September 13 2016

Categories: NHS Choices

Coil 'more effective' than morning after pill

Mon, 12/09/2016 - 18:30

"Women should use the coil rather than the morning-after pill as emergency contraception, according to official new guidelines," the Mail Online reports.

The guidelines, from the National Institute for Health and Care Excellence (NICE), cite previous research showing the coil has a lower failure rate than other forms of emergency contraception.

The coil, also known as intrauterine device (IUD), is a small, T-shaped contraceptive device made from plastic and copper. It's inserted into the uterus by a trained health professional. It may prevent an egg from implanting in your womb or being fertilised.

This isn't "news" as such – it has long been known that the contraceptive coil is more effective and can prevent unwanted pregnancy up to five days after unprotected intercourse, compared to only a few days with the morning-after pill. It also has other advantages, including that it can be used as an ongoing method of contraception to prevent further need for emergency contraception or unwanted pregnancy. 

Where did the guidance come from?

The National Institute for Health and Care Excellence (NICE), is the guideline body that provides national guidance on health and social care issues.

The current guideline on contraception is what is known as a Quality Standard. These documents set out the priority areas for improvements to the quality of care delivery across the country. They give a list of statements that will help improve and standardise care.

The contraception quality standard covers all methods of contraception, not just emergency, but does not cover related sexual health issues such as sexually transmitted infections. Quality Standards accompany other clinical guidelines that give recommendations on how conditions should be diagnosed and managed.

The information on coils, injections and implants has been drawn from NICE's clinical guideline on long acting reversible contraception.

Information on other contraceptive methods, including pills and condoms, has been drawn from guidelines produced by the Faculty of Sexual and Reproductive Healthcare (FSRH).


Why was the guidance needed?

As NICE says, it is estimated that almost one in five pregnancies are unplanned, with younger people at greater risk. However, things are improving – since 1998 the under-18 conception rate is said to have halved.

Between 2013 and 2014 there was a 6.8% decrease in rates, giving a conception rate of about 23 per 1,000 15-17 year olds, which is the lowest it's been since the end of the 1960s.

There remains room to improve though. In 2014 there were also 184,571 terminations or abortions, with the highest rate among young women in their early 20s at 28 per 1,000 pregnancies. For under-18s it was 11.1 per 1,000. More than a third of abortions are in women who've already had one or more previously.

In 2014/15, the vast majority of emergency contraception issued by sexual and reproductive health services was for the morning-after pill.


What does the guidance say about emergency contraception?

NICE's second quality statement is that "Women asking for emergency contraception are told that an intrauterine device is more effective than an oral method".

An intrauterine device (IUD) refers to the copper coil. It shouldn't be confused with the hormone-releasing intrauterine system (IUS); another long-term method of contraception. 

The IUD can be inserted up to five days after unprotected intercourse, and has a lower failure rate than the morning after pill.

Furthermore, it has the advantage that once it's inserted it provides an ongoing method of contraception which will reduce the risk of further unplanned pregnancies or need for emergency contraception.

If a woman wishes to have an IUD fitted as a form of emergency contraception, but the healthcare practitioner is not able to fit it there and then, NICE advises that the woman is given the morning after pill in the interim, and then directed to a service that can fit the coil.

There are two morning after pills. The standard morning after pill (levonorgestrel, brand name Levonelle) can only be taken up to three days after unprotected sex. The newer pill (ulipristal acetate, brand name ellaOne) is a longer acting pill and is also effective up to five days after unprotected sex.  



The quality standard emphasises best medical practice on this issue – women requesting emergency contraception should be advised on the benefits of the copper coil or IUD for several reasons. Namely, it being the method:

  • with the lowest failure rate
  • that can be used up to five days after sex
  • that provides a long-acting ongoing method of contraception

Despite the IUD's known effectiveness and benefits, in 2014/15, the vast majority of emergency contraception issued by sexual and reproductive health services was for the morning-after pill. It's worth taking a moment to consider why this may be the case.

The morning after pill can be purchased over the counter at a pharmacy – the woman doesn't need to see a doctor and they don't have to have an examination to have a coil fitted, both of which some women could naturally feel embarrassed about or averse to. Also, some women may not like the idea of long-term coil left in place.

It should also be recognised that while IUDs are effective at preventing pregnancy, they do not protect against sexually transmitted infections (STIs) in the same way as barrier methods of contraception such as condoms. And if you get an STI while you have an IUD, it could lead to a pelvic infection if not treated.

Nevertheless, in terms of effective emergency contraception, as Professor Gillian Leng, deputy chief executive of NICE says: "We want to empower women with the best information about all methods of contraception and their effectiveness so they can make an informed decision ... We also want to ensure women are told the coil is more effective than the pill as emergency contraception."

Dr Jan Wake, GP and member of the guideline development group said: "The advantage of the coil, on top of being more effective is that it can be retained and used as long term contraception, some can even be left in place for 10 years ... Timing however is essential and women deciding on the coil should make contact with the clinic they have been advised to attend as soon as is possible."

For more information on choices about contraception visit the NHS Choices Contraception Guide.

Links To The Headlines

Women should use the COIL instead of the morning after pill: NICE says method is 'more effective and would cut abortions'. Mail Online, September 8 2016

Coil 'better than morning-after pill'. BBC News, September 8 2016

Categories: NHS Choices

Statins are 'safe, effective and should be used more widely'

Fri, 09/09/2016 - 17:30

"The benefits of statins are hugely underestimated and far outweigh any harm," the Daily Mail reports.

A major review also argues that the risks of statins have been exaggerated by both the media and some sections of the medical profession.

The review in question explored a variety of evidence to weigh up the benefits and possible harms of the widely used cholesterol-lowering drugs.

It highlights that the benefits of statin therapy, which include reducing the risk of cardiovascular events like heart attack and stroke, far outweigh any possible side effects a patient may encounter as a result of the treatment. 

Statins have been controversial since they were first introduced as they are mainly used as a preventative measure for people at risk of, but with no history of, heart disease.

The drugs are an obvious target for "overmedicalisation" claims – that is, doctors treating people who don't actually need treatment.

The drugs have been associated with potential risks, such as harming the liver or, very rarely, causing muscle weakness or damage.

The review notes, for example, that for every 10,000 people who take standard-dose statin therapy for five years, only five would experience muscle weakness as a result.

Comparatively, between 500 and 1,000 cases of heart attack or stroke would have been avoided by the same number of people.

The authors also note that many side effects reported in placebo-controlled trials of statins may not in fact have been directly caused by the drugs.

Often, people who claimed statins were causing side effects continued to have the same side effects when given a dummy treatment.

Ironically, many of the media sources talking about side effects being "dangerously exaggerated" are the same ones exaggerating them in the first place – as we discussed in more detail in June 2016.

Dr Maureen Baker of the Royal College of General Practitioners (RCGP) said: "We hope this research reassures patients that in the majority of cases statins are safe and effective drugs – but in most cases where adverse side effects are seen, these are reversible by stopping taking statins."

Who produced the review?

The review was carried out by researchers from a variety of international institutes, including the University of Oxford and the London School of Hygiene and Tropical Medicine in the UK, Johns Hopkins University in the US, and the University of Sydney in Australia. 

The majority of researchers were funded by pharmaceutical companies. The study was published in the peer-reviewed journal, The Lancet.

The review was widely covered by a variety of both UK and international media outlets. The Daily Mail's headline read: "Statins ARE safe and we should give them to six million more people because benefits outweigh any harm, says biggest study ever".

But the review in question does not give such a definite opinion about the use of statins – rather, it highlights the importance of making an informed decision about any medical issue.

What evidence did they look at?

The review explored evidence from randomised controlled trials (RCTs) and observational studies, highlighting the strengths and limitations of each study design before delving into specific evidence on the safety and efficacy of statin therapy.

The authors argue that when it comes to weight of evidence, RCTs are more "weighty" as they carry less risk of bias than observational studies.

This is an important point – many of the reports about side effects and complications of statins came from observational studies, not RCTs.

The review generally reports outcomes in terms of the effects of taking a daily effective statin dose – for example, 40mg atorvastatin – in 10,000 patients over five years.

The methods behind how the literature was identified aren't described, and as such it isn't possible to say that this review was systematic in manner.

For example, the review doesn't mention whether literature databases were searched, search dates, search terms, or study eligibility for inclusion. This means there could be a chance that some relevant studies have not been included.

Main findings

Proven beneficial effects of statin therapy

  • Large-scale evidence shows that effective low-cost statin treatment, such as 40mg atorvastatin, can reduce low-density lipoprotein (LDL, or "bad") cholesterol levels by more than 50%. Five trials showed a reduction of 0.5mmol/L in LDL cholesterol levels after one year of therapy, 17 trials showed a reduction of 1.1mmol/L, and five further trials showed a reduction of >1.1mmol/L.
  • The reduction in LDL cholesterol levels was associated with a proportional reduction in major vascular event rates, such as heart attacks and related deaths, strokes and coronary revascularisations. For example, evidence showed each 1mmol/L reduction in LDL cholesterol was responsible for about a 25% reduction in the rate of major vascular events, and reducing cholesterol by 2mmol/L could reduce risk by about 45%.
  • The evidence indicated that reducing LDL cholesterol by 2mmol/L over five years in 10,000 people would prevent about 1,000 vascular events in people who were taking a statin after a previous heart attack or stroke (secondary prevention). This means the drugs would prevent further events in 10% of high-risk patients.
  • For people taking statins because they had cardiovascular disease risk factors but had not yet had an event (primary prevention), the drugs would prevent events in 500 out of 10,000 people – benefiting 5%.

Possible harms of statin therapy

  • Statin therapy has been linked with a rare risk of muscle weakness (myopathy) and possibly increases the risk of new-onset diabetes and strokes caused by bleeding (haemorrhagic stroke). Statistics show that typically for 10,000 patients who take a standard-dose statin for five years, five individuals would suffer from myopathy and 5 to 10 people would suffer from a haemorrhagic stroke. This means the event rates are extremely low. For new cases of diabetes, the risk was slightly higher – 50 to 100 new cases per 10,000 over five years.
  • Any harmful effects caused by statin therapy can be reversed by stopping treatment, but the effects of heart attacks or strokes that occur when statin therapy has not been used may be devastating.

This review highlights that misleading claims made about the balance of safety and efficacy of statins may pose a serious threat to the public's health.

In the past, exaggerated reporting of side effect rates and the related media coverage may have led to some doctors having reservations about prescribing statins to patients who needed them.

The coverage may have also led to reduced compliance from patients as a result of raised awareness about perceived side effects.

Evidence shows statin therapy is underused by people at a high risk of suffering from a heart attack or stroke.

One such study showed that in Europe only 42% of individuals with prior cardiovascular disease were taking any form of cholesterol-lowering treatment.

Drug discontinuation rates are also high, particularly among people who have not suffered from recent cardiovascular events.

This review notes the importance of employing caution when making claims about the possible side effects of a drug, as patients and doctors may be dissuaded from using statin therapy despite the proven benefits.


This study reviews evidence from randomised controlled trials (RCTs) and observational studies to better evaluate the effects and safety of statin therapy.

It provides valuable data on the size of the benefits compared with the risks, informing a topic that has had much media coverage in recent times.

The researchers highlight that the benefits of statin therapy for people at risk of cardiovascular disease events far outweigh any possible side effects.

But it is still for a doctor and their patient to come to a conclusion about what the best treatment for them may be.

If you have been prescribed a statin, it is important that you keep taking this medication as prescribed.

If you have any concerns or experience any side effects you think could be caused by a statin, you should speak with your doctor.

They will be able to assess whether the effects could be caused by the drug and will be able to consider an alternative treatment if needed.

You can also reduce your cholesterol levels by making changes to your diet.

Try to avoid or cut down on the following foods, which are high in saturated fat:

  • fatty cuts of meat and meat products, such as sausages and pies
  • butter, ghee and lard
  • cream, soured cream, crème fraîche and ice cream
  • cheese, particularly hard cheese
  • cakes and biscuits
  • milk chocolate
  • coconut oil, coconut cream and palm oil 

Links To The Headlines

Statins ARE safe and we should give them to six million more people because benefits outweigh any harm, says biggest study ever. Daily Mail, September 9 2016

Statins review says benefits 'underestimated'. BBC News, September 8 2016

Side-Effects Of Statins Dangerously Exaggerated, Review Warns. Sky News, September 9 2016

A third of adults should take statins, new research suggests. The Daily Telegraph, September 8 2016

Statins prevent 80,000 heart attacks and strokes a year in UK, study finds. The Guardian, September 8 2016

Millions of Brits taking statins for high cholesterol given news the drug is safe. Daily Mirror, September 8 2016

Links To Science

Collins R, Reith C, Emberson J, et al. Interpretation of the evidence for the efficacy and safety of statin therapy. The Lancet. Published online September 8 2016

Categories: NHS Choices

C-section babies 'more likely' to grow up obese

Wed, 07/09/2016 - 17:50

"Babies born by caesarean more likely to be obese as adults, study suggests," The Guardian reports.

A US study found that babies born via caesarean section had a 64% increased risk of becoming obese compared to their siblings born by vaginal delivery.

The study used responses from more than 22,000 children and young adults, and their mothers (all of whom were nurses) over a 16 year period.

Ultimately, the study doesn't prove that caesarean section causes obesity. An important limitation of the study, acknowledged by the researchers, is that they did not know the reasons why a caesarean section was carried out in the first place.

While the researchers tried to adjust their results for known risk factors for obesity in children, such as maternal age and pre-pregnancy weight, it is likely that other, unaccounted for, factors contributed to the risk of obesity. For example, maternal diet and breastfeeding were not investigated, which are known to influence children's weight.

The researchers do recommend that the potential increased risk of obesity should be explained to women considering having a caesarean section by choice (as opposed to the procedure being required due to a complicated labour).

Any increase in potential risk is just that; a possibility, not a guarantee set in stone. You can offset the increase by ensuring your child eats a healthy diet and is physically active. Read more advice about helping your child maintain a healthy weight and what you can do if you are concerned they may be overweight.


Where did the story come from?

The study was carried out by researchers from several US institutions including the Harvard TH Chan School of Public Health, the Brigham and Women's Hospital and Harvard Medical School and The Dartmouth Institute for Health Policy and Clinical Practice. Funding came from the National Institutes of Health, US. There were no conflicts of interest declared by the authors.

The study was published in the peer-reviewed journal JAMA Pediatrics.

While the UK media's reporting of the story was generally accurate, The Sun included an unhelpful section listing potential risks of having a caesarean without clarifying that the risk of some of these outcomes (such as bladder damage) is extremely small.


What kind of research was this?

This was a prospective cohort study using data collected from questionnaires completed by people in the US. These studies are a good way to find links between factors, in this case caesarean birth and obesity in childhood, adolescence and early adulthood. They cannot prove that one causes the other – that caesarean section caused obesity, however, as an experimental study would not be ethical, this is the best study design for finding a possible link.


What did the research involve?

Researchers analysed data on 22,068 young adults from an ongoing study in the US called the Growing Up Today Study. Participants started completing questionnaires aged 9 to 14 in either 1996 or 2004 and continued to complete a questionnaire every one or two years until 2012.

Each follow up questionnaire asked participants' height and weight. Participants' mothers undertook a questionnaire in 2009 that asked them to recall factors such as mode of delivery (vaginal or caesarean), BMI before pregnancy, diabetes during pregnancy, smoking and the age they gave birth.

In the data analysis, the authors adjusted the results to take into account many of these factors which could have influenced the mode of delivery and future obesity in the child.


What were the basic results?

Of the 22,068 children questioned, 4,921 had been born by caesarean section. Among all participants, there was a 13% risk of obesity by the end of follow up, aged 20 to 28.

  • Individuals born by caesarean delivery were 15% more likely to become obese during follow up than those born by vaginal delivery (adjusted risk ratio (aRR) 1.15, 95% confidence interval (CI) 1.06 to 1.26).
  • Those born by caesarean section had 64% higher odds of obesity compared with their siblings born by vaginal delivery (aRR 1.64, 95% CI 1.08 to 2.48).
  • Vaginal birth after a previous caesarean section was associated with a 31% lower risk of offspring obesity compared with those born to women with repeated caesarean deliveries (aRR 0.69, 95% CI 0.53 to 0.83).
How did the researchers interpret the results?

The researchers concluded there was an "association between caesarean delivery and increased risk of obesity in offspring that persisted through early adult life."

They also report "for the first time, to our knowledge, a protective effect of vaginal birth after caesarean delivery on obesity in offspring and a significant difference in risk of obesity between siblings whose modes of birth were discordant."

The researchers suggest that the findings may be related to differences in gut bacteria which are set at birth. Babies born by vaginal delivery have exposure to different bacteria which are known to be beneficial.



The authors have shown that there appears to be a link between mode of childbirth and obesity later in life for offspring.

The strengths of the study were that it was a large prospective cohort that examined BMI over a long period, meaning the risk of obesity could be seen from childhood into early adulthood. The reporting of information on pregnancy also allowed other factors to be accounted for.

However, there are a number of important considerations:

  • Babies born by caesarean section are less likely to have been breastfed, which has previously been linked with risk of obesity. This was not included in the adjusted analysis.
  • The mothers' diet was not taken into account, which has been shown to impact on the weight of offspring.
  • Obesity was measured using self-reported information, which may have resulted in inaccurate findings.
  • Finally, the mothers involved in the study were all nurses. They might not have been representative of the general population and therefore results might not be generalizable.

While it may be the case that some people born via caesarean have an increased tendency towards obesity, such a tendency can be overcome through the standard pattern of healthy eating and regular exercise.    

Links To The Headlines

Babies born by caesarean more likely to be obese as adults, study suggests. The Guardian, September 6 2016

Babies born by Caesarean section are more likely to be obese, research finds. The Independent, September 7 2016

Babies born by caesarean section at greater risk of obesity, Harvard study finds. The Daily Telegraph, September 7 2016

C-section babies are more likely to grow up FAT as they are exposed to lower levels of good bacteria. Daily Mail, September 7 2016

Babies born by caesarean 'are 15% more likely to become obese children than those born naturally'. Daily Mirror, September 6 2016

C-section delivery ‘DOES increase the risk your child will be obese’. The Sun, September 6 2016

C-section babies face raised obesity risk. The Times, September 7 2016 (subscription required)

Links To Science

Yuan C, Gaskins AJ, Blaine AI, et al. Association Between Cesarean Birth and Risk of Obesity in Offspring in Childhood, Adolescence, and Early Adulthood. JAMA Pediatrics. Published online September 6 2016

Categories: NHS Choices

Pollution particles in the brain 'linked to Alzheimer's disease'

Wed, 07/09/2016 - 16:28

"Air pollution particles linked to Alzheimer's found in human brain," Sky News reports after new research found tiny particles of magnetite – a potentially toxic by-product of traffic pollution – in samples of brain tissue.

The samples, obtained after death, were taken from 29 people from Mexico City and eight people from Manchester.

Magnetite is formed naturally in small quantities in the body, but the shapes of the naturally formed particles are jagged and irregular, while the particles found in the brain samples were spherical with smooth, fused surfaces.

Magnetite may increase oxidative damage – damage caused at the molecular level – to brain cells, especially in the presence of amyloid beta protein, a key protein linked to Alzheimer's disease.

While it's worrying to think pollution particles can enter the brain, it's unclear what role, if any, these particles really have in the development of the disease.

The people studied did not have Alzheimer's disease, although some of the eight people from the UK had a neurodegenerative disease.

The researchers have called for more work to be done to establish whether or not magnetite particles from air pollution play a role in causing Alzheimer's disease.

Independent experts have reacted with caution, saying this is as yet unknown.

Air pollution levels have fallen significantly in the UK in the last 40 years, but there has not been a corresponding fall in Alzheimer's cases, possibly making the link between the two harder to determine.

Where did the story come from?

The study was carried out by researchers from the University of Lancaster, the University of Oxford, the University of Glasgow, the University of Manchester, the University of Montana and Universidad Nacional Autonoma de Mexico.

It was funded by Alzheimer's Research UK, the Alzheimer's Society and the Medical Research Council. 

The study was published in the peer-reviewed Proceedings of the National Academy of Sciences journal.

The UK media covered the study responsibly for the most part, making it clear that we don't know for sure whether these particles are a cause of Alzheimer's, and quoting experts unconnected with the study to balance the views of the researchers.

What kind of research was this?

This experimental laboratory study analysed brain tissue samples using four types of particle analysis processes.

This type of study can show that these specific particles are present in the brains of the people studied, but nothing else.

It can't tell us whether these particles are found in everyone's brains or just in the brains of people who live in polluted areas, or whether they are more common in people with Alzheimer's disease. 

What did the research involve?

Researchers took samples of brain tissue from 29 people from Mexico City aged 3 to 85 years, and eight people from Manchester in the UK aged 62 to 92 years.

They analysed the samples using four different scanning and analysis procedures to examine the minerals, shape and composition of nanoparticles found in the frontal cortex of the brains.

The researchers looked at the number and size of the particles. They also compared the qualities of the particles found with previously identified naturally occurring magnetite particles, and also with particles found in air samples taken at roadsides in Lancaster.

What were the basic results?

The researchers found all the brain samples contained "abundant" magnetite particles "that match precisely the high-temperature magnetite nanospheres formed by combustion and/or friction-derived heating, which are prolific in urban, airborne particulate matter".

The concentrations were mainly highest among older people, although some of the samples taken from much younger Mexico City residents were also very high. Mexico City is known to have high levels of air pollution.

The researchers say they found two types of particles: the jagged types thought to form naturally, and the spherical, smooth type consistent with particles produced by air pollution.

These rounded forms also varied in size much more than the smaller naturally occurring variety.

How did the researchers interpret the results?

The researchers say their results may explain previous research, which found spherical particles of magnetite in the plaques and tangles of protein in brain tissue from people with Alzheimer's disease.

They also point to previous research from Taiwan, which found people living in areas with higher air pollution were more likely to get Alzheimer's disease. 

They say theoretically these particles could get from air into the brain via the olfactory nerve, which carries information about smell from the nose to the brain.

"Because of their combination of ultrafine size, specific brain toxicity, and ubiquity within airborne particulate matter, pollution-derived magnetite nanoparticles might require consideration as a possible Alzheimer's disease risk factor," they conclude.


Air pollution is known to be hazardous for human health as a cause of heart and lung disease. This study suggests microscopic particles found in pollution may also enter the brain. While that's a worrying thought, we don't know yet what effect that could have.

The study is quite limited in what it tells us. We know the researchers found particles of magnetite in all the brain samples studied, but as there was no control group – for example, people without neurodegenerative disease in the UK, or people from a less polluted part of Mexico – we don't know the significance of the finding.

And we don't know whether brains of people with Alzheimer's disease are more or less likely to contain magnetite particles than any other brains.

It's important that scientists investigate these findings further to answer some of these questions. But it doesn't mean the rest of us need to panic.

Avoiding pollution is sensible for health reasons if you can manage it – for example, by walking away from the edge of a busy road, or cycling through back streets – but it's not always possible.

Although nothing guarantees that you won't develop Alzheimer's disease, there are plenty of things you can do to reduce your risk of the condition:

Links To The Headlines

Air Pollution Particles Linked To Alzheimer's Found In Human Brain. Sky News, September 6 2016

Alzheimer's could be caused by toxic air pollution particles found in brain tissue. The Independent, September 6 2016

Pollution particles 'get into brain'. BBC News, September 5 2016

Toxic air pollution particles found in human brains. The Guardian, September 5 2016

'Air pollution' particles linked to Alzheimer's found in human brain. The Daily Telegraph, September 5 2016

Is this behind the rising rates of Alzheimer's? Scientists link disease to tiny particles absorbed by the brain from POLLUTION. Mail Online, September 5 2016

Links To Science

Maher BA, Ahmed IAM, Karloukovski V, et al. Magnetite pollution nanoparticles in the human brain. PNAS. Published online September 6 2016

Categories: NHS Choices